diff --git a/.cargo_vcs_info.json b/.cargo_vcs_info.json
index 75ac2a1..0fa03ad 100644
--- a/.cargo_vcs_info.json
+++ b/.cargo_vcs_info.json
@@ -1,5 +1,5 @@
 {
   "git": {
-    "sha1": "9a486adeee119bdf7ecb85ba627b8112fb7eff86"
+    "sha1": "eff71cffcc21f0b6d84a7dc3009cacb9ff16b4ea"
   }
 }
diff --git a/.circleci/config.yml b/.circleci/config.yml
index d5c0159..878e288 100644
--- a/.circleci/config.yml
+++ b/.circleci/config.yml
@@ -1,33 +1,33 @@
-version: 2.1
-
-executors:
-  rust-executor:
-    docker:
-      - image: rust:latest
-
-jobs:
-  build:
-    executor: rust-executor
-    steps:
-      - checkout
-      - run:
-          name: install cargo-web
-          command: cargo install -f cargo-web;
-      - run:
-          name: build
-          command: cargo build --verbose;
-      - run:
-          name: build --features stdweb
-          command: cargo web build --verbose --target wasm32-unknown-unknown --features "stdweb";
-      - run:
-          name: build --features wasm-bindgen
-          command: cargo build --verbose --target wasm32-unknown-unknown --features "wasm-bindgen";
-      - run:
-          name: build --features now
-          command: cargo build --verbose --features now;
-      - run:
-          name: build --features now stdweb
-          command: cargo web build --verbose --target wasm32-unknown-unknown --features "now stdweb";
-      - run:
-          name: build --features now wasm-bindgen
+version: 2.1
+
+executors:
+  rust-executor:
+    docker:
+      - image: rust:latest
+
+jobs:
+  build:
+    executor: rust-executor
+    steps:
+      - checkout
+      - run:
+          name: install cargo-web
+          command: cargo install -f cargo-web;
+      - run:
+          name: build
+          command: cargo build --verbose;
+      - run:
+          name: build --features stdweb
+          command: cargo web build --verbose --target wasm32-unknown-unknown --features "stdweb";
+      - run:
+          name: build --features wasm-bindgen
+          command: cargo build --verbose --target wasm32-unknown-unknown --features "wasm-bindgen";
+      - run:
+          name: build --features now
+          command: cargo build --verbose --features now;
+      - run:
+          name: build --features now stdweb
+          command: cargo web build --verbose --target wasm32-unknown-unknown --features "now stdweb";
+      - run:
+          name: build --features now wasm-bindgen
           command: cargo build --verbose --target wasm32-unknown-unknown --features "now wasm-bindgen";
\ No newline at end of file
diff --git a/.gitignore b/.gitignore
index 0c6aaf5..3722785 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,12 +1,12 @@
-*.swp
-*.swo
-*.so
-*.rlib
-*.dSYM
-*.dylib
-cargo.lock
-Cargo.lock
-target
-.idea
-wasm-pack.log
-bin
+*.swp
+*.swo
+*.so
+*.rlib
+*.dSYM
+*.dylib
+cargo.lock
+Cargo.lock
+target
+.idea
+wasm-pack.log
+bin
diff --git a/AUTHORS b/AUTHORS
index a4432b1..6f2ad5b 100644
--- a/AUTHORS
+++ b/AUTHORS
@@ -1,2 +1,2 @@
-Main developer:
+Main developer:
     * Sébastien Crozet <developer@crozet.re>
\ No newline at end of file
diff --git a/Android.bp b/Android.bp
index d5bc779..4d1f5e3 100644
--- a/Android.bp
+++ b/Android.bp
@@ -1,5 +1,4 @@
-// This file is generated by cargo2android.py --config cargo2android.json.
-// Do not modify this file as changes will be overridden on upgrade.
+// This file is generated by cargo2android.py --run --device --dependencies.
 
 package {
     default_applicable_licenses: ["external_rust_crates_instant_license"],
@@ -22,17 +21,12 @@
     name: "libinstant",
     host_supported: true,
     crate_name: "instant",
-    cargo_env_compat: true,
-    cargo_pkg_version: "0.1.12",
     srcs: ["src/lib.rs"],
     edition: "2018",
     rustlibs: [
         "libcfg_if",
     ],
-    apex_available: [
-        "//apex_available:platform",
-        "com.android.bluetooth",
-        "com.android.virt",
-    ],
-    min_sdk_version: "29",
 }
+
+// dependent_library ["feature_list"]
+//   cfg-if-1.0.0
diff --git a/CHANGELOGS.md b/CHANGELOGS.md
deleted file mode 100644
index 092d8ae..0000000
--- a/CHANGELOGS.md
+++ /dev/null
@@ -1,7 +0,0 @@
-# v0.1.12
-## Added 
-- Add `SystemTime` which works in both native and WASM environments.
-
-## Modified
-- The `now` function is always available now: there is no need to enable the `now` feature any more. The `now` feature
-  still exists (but doesn’t do anything) for backwards compatibility.
\ No newline at end of file
diff --git a/Cargo.toml b/Cargo.toml
index fcd0adf..58dea4e 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -3,16 +3,17 @@
 # When uploading crates to the registry Cargo will automatically
 # "normalize" Cargo.toml files for maximal compatibility
 # with all versions of Cargo and also rewrite `path` dependencies
-# to registry (e.g., crates.io) dependencies.
+# to registry (e.g., crates.io) dependencies
 #
-# If you are reading this file be aware that the original Cargo.toml
-# will likely look very different (and much more reasonable).
-# See Cargo.toml.orig for the original contents.
+# If you believe there's an error in this file please file an
+# issue against the rust-lang/cargo repository. If you're
+# editing this file be aware that the upstream Cargo.toml
+# will likely look very different (and much more reasonable)
 
 [package]
 edition = "2018"
 name = "instant"
-version = "0.1.12"
+version = "0.1.9"
 authors = ["sebcrozet <developer@crozet.re>"]
 description = "A partial replacement for std::time::Instant that works on WASM too."
 readme = "README.md"
@@ -26,7 +27,7 @@
 
 [features]
 inaccurate = []
-now = []
+now = ["time"]
 wasm-bindgen = ["js-sys", "wasm-bindgen_rs", "web-sys"]
 [target.asmjs-unknown-emscripten.dependencies.js-sys]
 version = "0.3"
@@ -45,6 +46,9 @@
 version = "0.3"
 features = ["Window", "Performance", "PerformanceTiming"]
 optional = true
+[target."cfg(not(any(feature = \"stdweb\", feature = \"wasm-bindgen\")))".dependencies.time]
+version = "0.2"
+optional = true
 [target.wasm32-unknown-emscripten.dependencies.js-sys]
 version = "0.3"
 optional = true
diff --git a/Cargo.toml.orig b/Cargo.toml.orig
index 8d55bd8..f6be57f 100644
--- a/Cargo.toml.orig
+++ b/Cargo.toml.orig
@@ -1,39 +1,42 @@
-[package]
-name = "instant"
-version = "0.1.12"
-authors = ["sebcrozet <developer@crozet.re>"]
-description = "A partial replacement for std::time::Instant that works on WASM too."
-repository = "https://github.com/sebcrozet/instant"
-readme = "README.md"
-license = "BSD-3-Clause"
-keywords = [ "time", "wasm" ]
-edition = "2018"
-
-[features]
-wasm-bindgen = ["js-sys", "wasm-bindgen_rs", "web-sys"]
-inaccurate = []
-now = []
-
-[dependencies]
-cfg-if = "1.0"
-
-[target.wasm32-unknown-unknown.dependencies]
-js-sys = { version = "0.3", optional = true }
-stdweb = { version = "0.4", optional = true }
-wasm-bindgen_rs = { package = "wasm-bindgen", version = "0.2", optional = true }
-web-sys = { version = "0.3", optional = true, features = ['Window', 'Performance', 'PerformanceTiming'] }
-
-[target.wasm32-unknown-emscripten.dependencies]
-js-sys = { version = "0.3", optional = true }
-stdweb = { version = "0.4", optional = true }
-wasm-bindgen_rs = { package = "wasm-bindgen", version = "0.2", optional = true }
-web-sys = { version = "0.3", optional = true, features = ['Window', 'Performance', 'PerformanceTiming'] }
-
-[target.asmjs-unknown-emscripten.dependencies]
-js-sys = { version = "0.3", optional = true }
-stdweb = { version = "0.4", optional = true }
-wasm-bindgen_rs = { package = "wasm-bindgen", version = "0.2", optional = true }
-web-sys = { version = "0.3", optional = true, features = ['Window', 'Performance', 'PerformanceTiming'] }
-
-[dev-dependencies]
-wasm-bindgen-test = "0.3"
+[package]
+name = "instant"
+version = "0.1.9"
+authors = ["sebcrozet <developer@crozet.re>"]
+description = "A partial replacement for std::time::Instant that works on WASM too."
+repository = "https://github.com/sebcrozet/instant"
+readme = "README.md"
+license = "BSD-3-Clause"
+keywords = [ "time", "wasm" ]
+edition = "2018"
+
+[features]
+now = [ "time" ]
+wasm-bindgen = ["js-sys", "wasm-bindgen_rs", "web-sys"]
+inaccurate = []
+
+[dependencies]
+cfg-if = "1.0"
+
+[target.'cfg(not(any(feature = "stdweb", feature = "wasm-bindgen")))'.dependencies]
+time = { version = "0.2", optional = true }
+
+[target.wasm32-unknown-unknown.dependencies]
+js-sys = { version = "0.3", optional = true }
+stdweb = { version = "0.4", optional = true }
+wasm-bindgen_rs = { package = "wasm-bindgen", version = "0.2", optional = true }
+web-sys = { version = "0.3", optional = true, features = ['Window', 'Performance', 'PerformanceTiming'] }
+
+[target.wasm32-unknown-emscripten.dependencies]
+js-sys = { version = "0.3", optional = true }
+stdweb = { version = "0.4", optional = true }
+wasm-bindgen_rs = { package = "wasm-bindgen", version = "0.2", optional = true }
+web-sys = { version = "0.3", optional = true, features = ['Window', 'Performance', 'PerformanceTiming'] }
+
+[target.asmjs-unknown-emscripten.dependencies]
+js-sys = { version = "0.3", optional = true }
+stdweb = { version = "0.4", optional = true }
+wasm-bindgen_rs = { package = "wasm-bindgen", version = "0.2", optional = true }
+web-sys = { version = "0.3", optional = true, features = ['Window', 'Performance', 'PerformanceTiming'] }
+
+[dev-dependencies]
+wasm-bindgen-test = "0.3"
diff --git a/LICENSE b/LICENSE
index f8062f3..a301457 100644
--- a/LICENSE
+++ b/LICENSE
@@ -1,27 +1,27 @@
-Copyright (c) 2019, Sébastien Crozet
-All rights reserved.
-
-Redistribution and use in source and binary forms, with or without
-modification, are permitted provided that the following conditions are met:
-
-1. Redistributions of source code must retain the above copyright notice, this
-   list of conditions and the following disclaimer.
-
-2. Redistributions in binary form must reproduce the above copyright notice,
-   this list of conditions and the following disclaimer in the documentation
-   and/or other materials provided with the distribution.
-
-3. Neither the name of the author nor the names of its contributors may be used
-   to endorse or promote products derived from this software without specific
-   prior written permission.
-
-THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
-ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
-WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
-DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
-FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
-DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
-SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
-CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
-OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
-OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+Copyright (c) 2019, Sébastien Crozet
+All rights reserved.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are met:
+
+1. Redistributions of source code must retain the above copyright notice, this
+   list of conditions and the following disclaimer.
+
+2. Redistributions in binary form must reproduce the above copyright notice,
+   this list of conditions and the following disclaimer in the documentation
+   and/or other materials provided with the distribution.
+
+3. Neither the name of the author nor the names of its contributors may be used
+   to endorse or promote products derived from this software without specific
+   prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
+ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
diff --git a/METADATA b/METADATA
index 8a1e612..c8d8100 100644
--- a/METADATA
+++ b/METADATA
@@ -7,13 +7,13 @@
   }
   url {
     type: ARCHIVE
-    value: "https://static.crates.io/crates/instant/instant-0.1.12.crate"
+    value: "https://static.crates.io/crates/instant/instant-0.1.9.crate"
   }
-  version: "0.1.12"
+  version: "0.1.9"
   license_type: NOTICE
   last_upgrade_date {
-    year: 2022
-    month: 3
-    day: 1
+    year: 2020
+    month: 11
+    day: 19
   }
 }
diff --git a/README.md b/README.md
index 0e35ad6..ecda215 100644
--- a/README.md
+++ b/README.md
@@ -1,143 +1,144 @@
-# Instant
-
-If you call `std::time::Instant::now()` on a WASM platform, it will panic. This crate provides a partial
-replacement for `std::time::Instant` that works on WASM too. This defines the type `instant::Instant` which is:
-
-* A struct emulating the behavior of **std::time::Instant** if you are targeting `wasm32-unknown-unknown` or `wasm32-unknown-asmjs`
-**and** you enabled either the `stdweb` or the `wasm-bindgen` feature. This emulation is based on the javascript `performance.now()` function.
-* A type alias for `std::time::Instant` otherwise.
-
-
-
-Note that even if the **stdweb** or **wasm-bindgen** feature is enabled, this crate will continue to rely on `std::time::Instant`
-as long as you are not targeting wasm32. This allows for portable code that will work on both native and WASM platforms.
-
-This crate also exports the function `instant::now()` which returns a representation of the current time as an `f64`, expressed in milliseconds, in a platform-agnostic way. `instant::now()` will either:
-
-* Call `performance.now()` when compiling for a WASM platform with the features **stdweb** or **wasm-bindgen** enabled, or using a custom javascript function.
-* Return the time elapsed since the *Unix Epoch* on *native*, *non-WASM* platforms.
-
-*Note*: The old feature, `now`, has been deprecated. `instant::now()` is always exported and the `now` feature flag no longer has any effect. It remains listed in `Cargo.toml` to avoid introducing breaking changes and may be removed in future versions.
-
-## Examples
-### Using `instant` for a native platform.
-_Cargo.toml_:
-```toml
-[dependencies]
-instant = "0.1"
-```
-
-_main.rs_:
-```rust
-fn main() {
-    // Will be the same as `std::time::Instant`.
-    let now = instant::Instant::now();
-}
-```
-
------
-
-### Using `instant` for a WASM platform.
-This example shows the use of the `stdweb` feature. It would be similar with `wasm-bindgen`.
-
-_Cargo.toml_:
-```toml
-[dependencies]
-instant = { version = "0.1", features = [ "stdweb" ] }
-```
-
-_main.rs_:
-```rust
-fn main() {
-    // Will emulate `std::time::Instant` based on `performance.now()`.
-    let now = instant::Instant::now();
-}
-```
-
------
-
-### Using `instant` for a WASM platform where `performance.now()` is not available.
-This example shows the use of the `inaccurate` feature.
-
-_Cargo.toml_:
-```toml
-[dependencies]
-instant = { version = "0.1", features = [ "wasm-bindgen", "inaccurate" ] }
-```
-
-_main.rs_:
-```rust
-fn main() {
-    // Will emulate `std::time::Instant` based on `Date.now()`.
-    let now = instant::Instant::now();
-}
-```
-
-
------
-
-### Using `instant` for any platform enabling a feature transitively.
-_Cargo.toml_:
-```toml
-[features]
-stdweb = [ "instant/stdweb" ]
-wasm-bindgen = [ "instant/wasm-bindgen" ]
-
-[dependencies]
-instant = "0.1"
-```
-
-_lib.rs_:
-```rust
-fn my_function() {
-    // Will select the proper implementation depending on the
-    // feature selected by the user.
-    let now = instant::Instant::now();
-}
-```
-
------
-
-### Using `instant::now()`
-_Cargo.toml_:
-```toml
-[features]
-stdweb = [ "instant/stdweb" ]
-wasm-bindgen = [ "instant/wasm-bindgen" ]
-
-[dependencies]
-instant = "0.1"
-```
-
-_lib.rs_:
-```rust
-fn my_function() {
-    // Will select the proper implementation depending on the
-    // feature selected by the user.
-    let now_instant = instant::Instant::now();
-    let now_milliseconds = instant::now(); // In milliseconds.
-}
-```
-
-### Using the feature `now` without `stdweb` or `wasm-bindgen`.
-_Cargo.toml_:
-```toml
-[dependencies]
-instant = "0.1"
-```
-
-_lib.rs_:
-```rust
-fn my_function() {
-    // Will use the 'now' javascript implementation.
-    let now_instant = instant::Instant::now();
-    let now_milliseconds = instant::now(); // In milliseconds.
-}
-```
-
-_javascript WASM bindings file_:
-```js
-function now() {
-	return Date.now() / 1000.0;
-}
-```
+# Instant
+
+If you call `std::time::Instant::now()` on a WASM platform, it will panic. This crate provides a partial
+replacement for `std::time::Instant` that works on WASM too. This defines the type `instant::Instant` which is:
+
+* A struct emulating the behavior of **std::time::Instant** if you are targeting `wasm32-unknown-unknown` or `wasm32-unknown-asmjs`
+**and** you enabled either the `stdweb` or the `wasm-bindgen` feature. This emulation is based on the javascript `performance.now()` function.
+* A type alias for `std::time::Instant` otherwise.
+
+
+
+Note that even if the **stdweb** or **wasm-bindgen** feature is enabled, this crate will continue to rely on `std::time::Instant`
+as long as you are not targeting wasm32. This allows for portable code that will work on both native and WASM platforms.
+
+### The feature `now`.
+By enabling the feature `now` the function `instant::now()` will be exported and will either:
+
+* Call `performance.now()` when compiling for a WASM platform with the features **stdweb** or **wasm-bindgen** enabled, or using a custom javascript function.
+* Call `time::precise_time_s() * 1000.0` otherwise.
+
+The result is expressed in milliseconds.
+
+## Examples
+### Using `instant` for a native platform.
+_Cargo.toml_:
+```toml
+[dependencies]
+instant = "0.1"
+```
+
+_main.rs_:
+```rust
+fn main() {
+    // Will be the same as `std::time::Instant`.
+    let now = instant::Instant::new();
+}
+```
+
+-----
+
+### Using `instant` for a WASM platform.
+This example shows the use of the `stdweb` feature. It would be similar with `wasm-bindgen`.
+
+_Cargo.toml_:
+```toml
+[dependencies]
+instant = { version = "0.1", features = [ "stdweb" ] }
+```
+
+_main.rs_:
+```rust
+fn main() {
+    // Will emulate `std::time::Instant` based on `performance.now()`.
+    let now = instant::Instant::new();
+}
+```
+
+-----
+
+### Using `instant` for a WASM platform where `performance.now()` is not available.
+This example shows the use of the `inaccurate` feature.
+
+_Cargo.toml_:
+```toml
+[dependencies]
+instant = { version = "0.1", features = [ "wasm-bindgen", "inaccurate" ] }
+```
+
+_main.rs_:
+```rust
+fn main() {
+    // Will emulate `std::time::Instant` based on `Date.now()`.
+    let now = instant::Instant::new();
+}
+```
+
+
+-----
+
+### Using `instant` for any platform enabling a feature transitively.
+_Cargo.toml_:
+```toml
+[features]
+stdweb = [ "instant/stdweb" ]
+wasm-bindgen = [ "instant/wasm-bindgen" ]
+
+[dependencies]
+instant = "0.1"
+```
+
+_lib.rs_:
+```rust
+fn my_function() {
+    // Will select the proper implementation depending on the
+    // feature selected by the user.
+    let now = instant::Instant::new();
+}
+```
+
+-----
+
+### Using the feature `now`.
+_Cargo.toml_:
+```toml
+[features]
+stdweb = [ "instant/stdweb" ]
+wasm-bindgen = [ "instant/wasm-bindgen" ]
+
+[dependencies]
+instant = { version = "0.1", features = [ "now" ] }
+```
+
+_lib.rs_:
+```rust
+fn my_function() {
+    // Will select the proper implementation depending on the
+    // feature selected by the user.
+    let now_instant = instant::Instant::new();
+    let now_milliseconds = instant::now(); // In milliseconds.
+}
+```
+
+### Using the feature `now` without `stdweb` or `wasm-bindgen`.
+_Cargo.toml_:
+```toml
+[dependencies]
+instant = { version = "0.", features = [ "now" ] }
+```
+
+_lib.rs_:
+```rust
+fn my_function() {
+    // Will use the 'now' javascript implementation.
+    let now_instant = instant::Instant::new();
+    let now_milliseconds = instant::now(); // In milliseconds.
+}
+```
+
+_javascript WASM bindings file_:
+```js
+function now() {
+	return Date.now() / 1000.0;
+}
+```
diff --git a/TEST_MAPPING b/TEST_MAPPING
new file mode 100644
index 0000000..7213fe9
--- /dev/null
+++ b/TEST_MAPPING
@@ -0,0 +1,8 @@
+// Generated by cargo2android.py for tests that depend on this crate.
+{
+  "presubmit": [
+    {
+      "name": "parking_lot_core_device_test_src_lib"
+    }
+  ]
+}
diff --git a/cargo2android.json b/cargo2android.json
deleted file mode 100644
index e48e3b8..0000000
--- a/cargo2android.json
+++ /dev/null
@@ -1,10 +0,0 @@
-{
-  "apex-available": [
-    "//apex_available:platform",
-    "com.android.bluetooth",
-    "com.android.virt"
-  ],
-  "device": true,
-  "min-sdk-version": "29",
-  "run": true
-}
diff --git a/src/lib.rs b/src/lib.rs
index 00d59e7..077c9d4 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -1,22 +1,22 @@
-cfg_if::cfg_if! {
-    if #[cfg(any(
-        all(target_arch = "wasm32", not(target_os = "wasi")),
-        target_arch = "asmjs"
-    ))] {
-        #[cfg(all(feature = "stdweb", not(feature = "wasm-bindgen")))]
-        #[macro_use]
-        extern crate stdweb;
-
-        mod wasm;
-        pub use wasm::Instant;
-        pub use crate::wasm::now;
-        pub use wasm::SystemTime;
-    } else {
-        mod native;
-        pub use native::Instant;
-        pub use native::now;
-        pub use native::SystemTime;
-    }
-}
-
-pub use std::time::Duration;
+cfg_if::cfg_if! {
+    if #[cfg(any(
+        all(target_arch = "wasm32", not(target_os = "wasi")),
+        target_arch = "asmjs"
+    ))] {
+        #[cfg(all(feature = "stdweb", not(feature = "wasm-bindgen")))]
+        #[macro_use]
+        extern crate stdweb;
+
+        mod wasm;
+        pub use wasm::Instant;
+        #[cfg(feature = "now")]
+        pub use crate::wasm::now;
+    } else {
+        mod native;
+        pub use native::Instant;
+        #[cfg(feature = "now")]
+        pub use native::now;
+    }
+}
+
+pub use std::time::Duration;
diff --git a/src/native.rs b/src/native.rs
index 37b34f3..37d5da4 100644
--- a/src/native.rs
+++ b/src/native.rs
@@ -1,9 +1,7 @@
-pub type Instant = std::time::Instant;
-pub type SystemTime = std::time::SystemTime;
-
-/// The current time, expressed in milliseconds since the Unix Epoch.
-pub fn now() -> f64 {
-    std::time::SystemTime::now().duration_since(std::time::SystemTime::UNIX_EPOCH)
-                                .expect("System clock was before 1970.")
-                                .as_secs_f64() * 1000.0
-}
+pub type Instant = std::time::Instant;
+
+/// The current time, in milliseconds.
+#[cfg(feature = "now")]
+pub fn now() -> f64 {
+    time::precise_time_s() * 1000.0
+}
diff --git a/src/wasm.rs b/src/wasm.rs
index f11b82a..986bbf6 100644
--- a/src/wasm.rs
+++ b/src/wasm.rs
@@ -1,240 +1,138 @@
-use std::cmp::Ordering;
-use std::ops::{Add, AddAssign, Sub, SubAssign};
-use std::time::Duration;
-
-#[derive(Copy, Clone, Debug, PartialEq, PartialOrd, Hash)]
-pub struct Instant(Duration);
-
-impl Ord for Instant {
-    fn cmp(&self, other: &Self) -> std::cmp::Ordering {
-        self.partial_cmp(other)
-            .expect("an instant should never be NaN or Inf.")
-    }
-}
-impl Eq for Instant {}
-
-impl Instant {
-    #[inline]
-    pub fn now() -> Self {
-        Instant(duration_from_f64(now()))
-    }
-
-    #[inline]
-    pub fn duration_since(&self, earlier: Instant) -> Duration {
-        assert!(
-            earlier.0 <= self.0,
-            "`earlier` cannot be later than `self`."
-        );
-        self.0 - earlier.0
-    }
-
-    #[inline]
-    pub fn elapsed(&self) -> Duration {
-        Self::now().duration_since(*self)
-    }
-
-    /// Returns `Some(t)` where `t` is the time `self + duration` if `t` can be represented as
-    /// `Instant` (which means it's inside the bounds of the underlying data structure), `None`
-    /// otherwise.
-    #[inline]
-    pub fn checked_add(&self, duration: Duration) -> Option<Instant> {
-        self.0.checked_add(duration).map(Instant)
-    }
-
-    /// Returns `Some(t)` where `t` is the time `self - duration` if `t` can be represented as
-    /// `Instant` (which means it's inside the bounds of the underlying data structure), `None`
-    /// otherwise.
-    #[inline]
-    pub fn checked_sub(&self, duration: Duration) -> Option<Instant> {
-        self.0.checked_sub(duration).map(Instant)
-    }
-
-    /// Returns the amount of time elapsed from another instant to this one, or None if that
-    /// instant is later than this one.
-    #[inline]
-    pub fn checked_duration_since(&self, earlier: Instant) -> Option<Duration> {
-        if earlier.0 > self.0 {
-            None
-        } else {
-            Some(self.0 - earlier.0)
-        }
-    }
-
-    /// Returns the amount of time elapsed from another instant to this one, or zero duration if
-    /// that instant is later than this one.
-    #[inline]
-    pub fn saturating_duration_since(&self, earlier: Instant) -> Duration {
-        self.checked_duration_since(earlier).unwrap_or_default()
-    }
-}
-
-impl Add<Duration> for Instant {
-    type Output = Self;
-
-    #[inline]
-    fn add(self, rhs: Duration) -> Self {
-        Instant(self.0 + rhs)
-    }
-}
-
-impl AddAssign<Duration> for Instant {
-    #[inline]
-    fn add_assign(&mut self, rhs: Duration) {
-        self.0 += rhs
-    }
-}
-
-impl Sub<Duration> for Instant {
-    type Output = Self;
-
-    #[inline]
-    fn sub(self, rhs: Duration) -> Self {
-        Instant(self.0 - rhs)
-    }
-}
-
-impl Sub<Instant> for Instant {
-    type Output = Duration;
-
-    #[inline]
-    fn sub(self, rhs: Instant) -> Duration {
-        self.duration_since(rhs)
-    }
-}
-
-impl SubAssign<Duration> for Instant {
-    #[inline]
-    fn sub_assign(&mut self, rhs: Duration) {
-        self.0 -= rhs
-    }
-}
-
-fn duration_from_f64(millis: f64) -> Duration {
-    Duration::from_millis(millis.trunc() as u64)
-        + Duration::from_nanos((millis.fract() * 1.0e6) as u64)
-}
-
-#[cfg(all(feature = "stdweb", not(feature = "wasm-bindgen")))]
-#[allow(unused_results)] // Needed because the js macro triggers it.
-pub fn now() -> f64 {
-    use stdweb::unstable::TryInto;
-
-    // https://developer.mozilla.org/en-US/docs/Web/API/Performance/now
-    #[cfg(not(feature = "inaccurate"))]
-    let v = js! { return performance.now(); };
-    #[cfg(feature = "inaccurate")]
-    let v = js! { return Date.now(); };
-    v.try_into().unwrap()
-}
-
-#[cfg(feature = "wasm-bindgen")]
-pub fn now() -> f64 {
-    #[cfg(not(feature = "inaccurate"))]
-    let now = {
-        use wasm_bindgen_rs::prelude::*;
-        use wasm_bindgen_rs::JsCast;
-        js_sys::Reflect::get(&js_sys::global(), &JsValue::from_str("performance"))
-            .expect("failed to get performance from global object")
-            .unchecked_into::<web_sys::Performance>()
-            .now()
-    };
-    #[cfg(feature = "inaccurate")]
-    let now = js_sys::Date::now();
-    now
-}
-
-// The JS now function is in a module so it won't have to be renamed
-#[cfg(not(any(feature = "wasm-bindgen", feature = "stdweb")))]
-mod js {
-    extern "C" {
-        #[cfg(not(target_os = "emscripten"))]
-        pub fn now() -> f64;
-        #[cfg(target_os = "emscripten")]
-        pub fn _emscripten_get_now() -> f64;
-    }
-}
-// Make the unsafe extern function "safe" so it can be called like the other 'now' functions
-#[cfg(not(any(feature = "wasm-bindgen", feature = "stdweb")))]
-pub fn now() -> f64 {
-    #[cfg(not(target_os = "emscripten"))]
-    return unsafe { js::now() };
-    #[cfg(target_os = "emscripten")]
-    return unsafe { js::_emscripten_get_now() };
-}
-
-/// Returns the number of millisecods elapsed since January 1, 1970 00:00:00 UTC.
-#[cfg(any(feature = "wasm-bindgen", feature = "stdweb"))]
-fn get_time() -> f64 {
-    #[cfg(feature = "wasm-bindgen")]
-    return js_sys::Date::now();
-    #[cfg(all(feature = "stdweb", not(feature = "wasm-bindgen")))]
-    {
-        let v = js! { return Date.now(); };
-        return v.try_into().unwrap();
-    }
-}
-
-#[derive(Copy, Clone, Debug, PartialEq, PartialOrd)]
-pub struct SystemTime(f64);
-
-impl SystemTime {
-    pub const UNIX_EPOCH: SystemTime = SystemTime(0.0);
-
-    pub fn now() -> SystemTime {
-        cfg_if::cfg_if! {
-            if #[cfg(any(feature = "wasm-bindgen", feature = "stdweb"))] {
-                SystemTime(get_time())
-            } else {
-                SystemTime(now())
-            }
-        }
-    }
-
-    pub fn duration_since(&self, earlier: SystemTime) -> Result<Duration, ()> {
-        let dur_ms = self.0 - earlier.0;
-        if dur_ms < 0.0 {
-            return Err(());
-        }
-        Ok(Duration::from_millis(dur_ms as u64))
-    }
-
-    pub fn elapsed(&self) -> Result<Duration, ()> {
-        self.duration_since(SystemTime::now())
-    }
-
-    pub fn checked_add(&self, duration: Duration) -> Option<SystemTime> {
-        Some(*self + duration)
-    }
-
-    pub fn checked_sub(&self, duration: Duration) -> Option<SystemTime> {
-        Some(*self - duration)
-    }
-}
-
-impl Add<Duration> for SystemTime {
-    type Output = SystemTime;
-
-    fn add(self, other: Duration) -> SystemTime {
-        SystemTime(self.0 + other.as_millis() as f64)
-    }
-}
-
-impl Sub<Duration> for SystemTime {
-    type Output = SystemTime;
-
-    fn sub(self, other: Duration) -> SystemTime {
-        SystemTime(self.0 - other.as_millis() as f64)
-    }
-}
-
-impl AddAssign<Duration> for SystemTime {
-    fn add_assign(&mut self, rhs: Duration) {
-        *self = *self + rhs;
-    }
-}
-
-impl SubAssign<Duration> for SystemTime {
-    fn sub_assign(&mut self, rhs: Duration) {
-        *self = *self - rhs;
-    }
-}
+use std::ops::{Add, AddAssign, Sub, SubAssign};
+use std::time::Duration;
+
+#[derive(Copy, Clone, Debug, PartialEq, PartialOrd, Hash)]
+pub struct Instant(Duration);
+
+impl Ord for Instant {
+    fn cmp(&self, other: &Self) -> std::cmp::Ordering {
+        self.partial_cmp(other)
+            .expect("an instant should never be NaN or Inf.")
+    }
+}
+impl Eq for Instant {}
+
+impl Instant {
+    #[inline]
+    pub fn now() -> Self {
+        Instant(duration_from_f64(now()))
+    }
+
+    #[inline]
+    pub fn duration_since(&self, earlier: Instant) -> Duration {
+        assert!(
+            earlier.0 <= self.0,
+            "`earlier` cannot be later than `self`."
+        );
+        self.0 - earlier.0
+    }
+
+    #[inline]
+    pub fn elapsed(&self) -> Duration {
+        Self::now().duration_since(*self)
+    }
+
+    /// Returns `Some(t)` where `t` is the time `self + duration` if `t` can be represented as
+    /// `Instant` (which means it's inside the bounds of the underlying data structure), `None`
+    /// otherwise.
+    #[inline]
+    pub fn checked_add(&self, duration: Duration) -> Option<Instant> {
+        self.0.checked_add(duration).map(Instant)
+    }
+
+    /// Returns `Some(t)` where `t` is the time `self - duration` if `t` can be represented as
+    /// `Instant` (which means it's inside the bounds of the underlying data structure), `None`
+    /// otherwise.
+    #[inline]
+    pub fn checked_sub(&self, duration: Duration) -> Option<Instant> {
+        self.0.checked_sub(duration).map(Instant)
+    }
+}
+
+impl Add<Duration> for Instant {
+    type Output = Self;
+
+    #[inline]
+    fn add(self, rhs: Duration) -> Self {
+        Instant(self.0 + rhs)
+    }
+}
+
+impl AddAssign<Duration> for Instant {
+    #[inline]
+    fn add_assign(&mut self, rhs: Duration) {
+        self.0 += rhs
+    }
+}
+
+impl Sub<Duration> for Instant {
+    type Output = Self;
+
+    #[inline]
+    fn sub(self, rhs: Duration) -> Self {
+        Instant(self.0 - rhs)
+    }
+}
+
+impl Sub<Instant> for Instant {
+    type Output = Duration;
+
+    #[inline]
+    fn sub(self, rhs: Instant) -> Duration {
+        self.duration_since(rhs)
+    }
+}
+
+impl SubAssign<Duration> for Instant {
+    #[inline]
+    fn sub_assign(&mut self, rhs: Duration) {
+        self.0 -= rhs
+    }
+}
+
+fn duration_from_f64(millis: f64) -> Duration {
+    Duration::from_millis(millis.trunc() as u64)
+        + Duration::from_nanos((millis.fract() * 1.0e6) as u64)
+}
+
+#[cfg(all(feature = "stdweb", not(feature = "wasm-bindgen")))]
+#[allow(unused_results)] // Needed because the js macro triggers it.
+pub fn now() -> f64 {
+    use stdweb::unstable::TryInto;
+
+    // https://developer.mozilla.org/en-US/docs/Web/API/Performance/now
+    #[cfg(not(feature = "inaccurate"))]
+    let v = js! { return performance.now(); };
+    #[cfg(feature = "inaccurate")]
+    let v = js! { return Date.now(); };
+    v.try_into().unwrap()
+}
+
+#[cfg(feature = "wasm-bindgen")]
+pub fn now() -> f64 {
+    #[cfg(not(feature = "inaccurate"))]
+    let now = {
+        use wasm_bindgen_rs::prelude::*;
+        use wasm_bindgen_rs::JsCast;
+        js_sys::Reflect::get(&js_sys::global(), &JsValue::from_str("performance"))
+            .expect("failed to get performance from global object")
+            .unchecked_into::<web_sys::Performance>()
+            .now()
+    };
+    #[cfg(feature = "inaccurate")]
+    let now = js_sys::Date::now();
+    now
+}
+
+// The JS now function is in a module so it won't have to be renamed
+#[cfg(not(any(feature = "wasm-bindgen", feature = "stdweb")))]
+mod js {
+    extern "C" {
+        pub fn now() -> f64;
+    }
+}
+// Make the unsafe extern function "safe" so it can be called like the other 'now' functions
+#[cfg(not(any(feature = "wasm-bindgen", feature = "stdweb")))]
+pub fn now() -> f64 {
+    unsafe { js::now() }
+}
diff --git a/tests/wasm.rs b/tests/wasm.rs
index 7dacdc4..863eefd 100644
--- a/tests/wasm.rs
+++ b/tests/wasm.rs
@@ -1,57 +1,49 @@
-extern crate wasm_bindgen_test;
-
-use instant::{Instant, SystemTime};
-use std::time::Duration;
-use wasm_bindgen_test::*;
-
-wasm_bindgen_test_configure!(run_in_browser);
-// run these tests using: wasm-pack test --chrome --headless -- --features wasm-bindgen
-
-#[wasm_bindgen_test]
-fn test_instant_now() {
-    let now = Instant::now();
-    #[cfg(feature = "inaccurate")]
-    while now.elapsed().as_millis() == 0 {}
-    #[cfg(not(feature = "inaccurate"))]
-    assert!(now.elapsed().as_nanos() > 0);
-}
-
-#[wasm_bindgen_test]
-fn test_duration() {
-    let now = Instant::now();
-    let one_sec = Duration::from_secs(1);
-    assert!(now.elapsed() < one_sec);
-}
-
-// Duration::new will overflow when you have u64::MAX seconds and one billion nanoseconds.
-// <https://doc.rust-lang.org/std/time/struct.Duration.html#method.new>
-const ONE_BILLION: u32 = 1_000_000_000;
-
-#[wasm_bindgen_test]
-fn test_checked_add() {
-    let now = Instant::now();
-
-    assert!(now.checked_add(Duration::from_millis(1)).is_some());
-    assert_eq!(
-        None,
-        now.checked_add(Duration::new(u64::MAX, ONE_BILLION - 1))
-    );
-}
-
-#[wasm_bindgen_test]
-fn test_checked_sub() {
-    let now = Instant::now();
-
-    assert!(now.checked_sub(Duration::from_millis(1)).is_some());
-    assert!(now
-        .checked_sub(Duration::new(u64::MAX, ONE_BILLION - 1))
-        .is_none());
-}
-
-#[wasm_bindgen_test]
-fn test_system_time() {
-    assert!(SystemTime::UNIX_EPOCH
-        .duration_since(SystemTime::now())
-        .is_err());
-}
-
+extern crate wasm_bindgen_test;
+
+use instant::Instant;
+use std::time::Duration;
+use wasm_bindgen_test::*;
+
+wasm_bindgen_test_configure!(run_in_browser);
+// run these tests using: wasm-pack test --chrome --headless -- --features wasm-bindgen
+
+#[wasm_bindgen_test]
+fn test_instant_now() {
+    let now = Instant::now();
+    #[cfg(feature = "inaccurate")]
+    while now.elapsed().as_millis() == 0 {}
+    #[cfg(not(feature = "inaccurate"))]
+    assert!(now.elapsed().as_nanos() > 0);
+}
+
+#[wasm_bindgen_test]
+fn test_duration() {
+    let now = Instant::now();
+    let one_sec = Duration::from_secs(1);
+    assert!(now.elapsed() < one_sec);
+}
+
+// Duration::new will overflow when you have u64::MAX seconds and one billion nanoseconds.
+// <https://doc.rust-lang.org/std/time/struct.Duration.html#method.new>
+const ONE_BILLION: u32 = 1_000_000_000;
+
+#[wasm_bindgen_test]
+fn test_checked_add() {
+    let now = Instant::now();
+
+    assert!(now.checked_add(Duration::from_millis(1)).is_some());
+    assert_eq!(
+        None,
+        now.checked_add(Duration::new(u64::MAX, ONE_BILLION - 1))
+    );
+}
+
+#[wasm_bindgen_test]
+fn test_checked_sub() {
+    let now = Instant::now();
+
+    assert!(now.checked_sub(Duration::from_millis(1)).is_some());
+    assert!(now
+        .checked_sub(Duration::new(u64::MAX, ONE_BILLION - 1))
+        .is_none());
+}