diff --git a/.cargo_vcs_info.json b/.cargo_vcs_info.json
new file mode 100644
index 0000000..347708d
--- /dev/null
+++ b/.cargo_vcs_info.json
@@ -0,0 +1,5 @@
+{
+  "git": {
+    "sha1": "0701287eb68bbf2ec1f3b8e8012d577ddaf90938"
+  }
+}
diff --git a/Cargo.toml b/Cargo.toml
new file mode 100644
index 0000000..0d11564
--- /dev/null
+++ b/Cargo.toml
@@ -0,0 +1,43 @@
+# THIS FILE IS AUTOMATICALLY GENERATED BY CARGO
+#
+# 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
+#
+# 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 = "time-macros-impl"
+version = "0.1.1"
+authors = ["Jacob Pratt <the.z.cuber@gmail.com>"]
+description = "Procedural macros for the time crate."
+readme = "../README.md"
+keywords = ["date", "time", "calendar", "duration"]
+categories = ["date-and-time"]
+license = "MIT OR Apache-2.0"
+repository = "https://github.com/time-rs/time"
+
+[lib]
+proc-macro = true
+[dependencies.proc-macro-hack]
+version = "0.5"
+
+[dependencies.proc-macro2]
+version = "1"
+
+[dependencies.quote]
+version = "1"
+
+[dependencies.standback]
+version = "0.2"
+default-features = false
+
+[dependencies.syn]
+version = "1"
+features = ["proc-macro", "parsing", "printing", "derive"]
+default-features = false
diff --git a/Cargo.toml.orig b/Cargo.toml.orig
new file mode 100644
index 0000000..3ef79fc
--- /dev/null
+++ b/Cargo.toml.orig
@@ -0,0 +1,22 @@
+[package]
+name = "time-macros-impl"
+version = "0.1.1"
+authors = ["Jacob Pratt <the.z.cuber@gmail.com>"]
+edition = "2018"
+repository = "https://github.com/time-rs/time"
+keywords = ["date", "time", "calendar", "duration"]
+categories = ["date-and-time"]
+readme = "../README.md"
+license = "MIT OR Apache-2.0"
+description = "Procedural macros for the time crate."
+
+[dependencies]
+proc-macro2 = "1"
+# I'm not entirely sure why `derive` is necessary here, but it fails without it.
+syn = { version = "1", default-features = false, features = ["proc-macro", "parsing", "printing", "derive"] }
+quote = "1"
+proc-macro-hack = "0.5"
+standback = { version = "0.2", default-features = false }
+
+[lib]
+proc-macro = true
diff --git a/LICENSE b/LICENSE
new file mode 120000
index 0000000..a1c76e3
--- /dev/null
+++ b/LICENSE
@@ -0,0 +1 @@
+LICENSE-Apache
\ No newline at end of file
diff --git a/LICENSE-Apache b/LICENSE-Apache
new file mode 100644
index 0000000..3d2fb46
--- /dev/null
+++ b/LICENSE-Apache
@@ -0,0 +1,202 @@
+
+                                 Apache License
+                           Version 2.0, January 2004
+                        http://www.apache.org/licenses/
+
+   TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION
+
+   1. Definitions.
+
+      "License" shall mean the terms and conditions for use, reproduction,
+      and distribution as defined by Sections 1 through 9 of this document.
+
+      "Licensor" shall mean the copyright owner or entity authorized by
+      the copyright owner that is granting the License.
+
+      "Legal Entity" shall mean the union of the acting entity and all
+      other entities that control, are controlled by, or are under common
+      control with that entity. For the purposes of this definition,
+      "control" means (i) the power, direct or indirect, to cause the
+      direction or management of such entity, whether by contract or
+      otherwise, or (ii) ownership of fifty percent (50%) or more of the
+      outstanding shares, or (iii) beneficial ownership of such entity.
+
+      "You" (or "Your") shall mean an individual or Legal Entity
+      exercising permissions granted by this License.
+
+      "Source" form shall mean the preferred form for making modifications,
+      including but not limited to software source code, documentation
+      source, and configuration files.
+
+      "Object" form shall mean any form resulting from mechanical
+      transformation or translation of a Source form, including but
+      not limited to compiled object code, generated documentation,
+      and conversions to other media types.
+
+      "Work" shall mean the work of authorship, whether in Source or
+      Object form, made available under the License, as indicated by a
+      copyright notice that is included in or attached to the work
+      (an example is provided in the Appendix below).
+
+      "Derivative Works" shall mean any work, whether in Source or Object
+      form, that is based on (or derived from) the Work and for which the
+      editorial revisions, annotations, elaborations, or other modifications
+      represent, as a whole, an original work of authorship. For the purposes
+      of this License, Derivative Works shall not include works that remain
+      separable from, or merely link (or bind by name) to the interfaces of,
+      the Work and Derivative Works thereof.
+
+      "Contribution" shall mean any work of authorship, including
+      the original version of the Work and any modifications or additions
+      to that Work or Derivative Works thereof, that is intentionally
+      submitted to Licensor for inclusion in the Work by the copyright owner
+      or by an individual or Legal Entity authorized to submit on behalf of
+      the copyright owner. For the purposes of this definition, "submitted"
+      means any form of electronic, verbal, or written communication sent
+      to the Licensor or its representatives, including but not limited to
+      communication on electronic mailing lists, source code control systems,
+      and issue tracking systems that are managed by, or on behalf of, the
+      Licensor for the purpose of discussing and improving the Work, but
+      excluding communication that is conspicuously marked or otherwise
+      designated in writing by the copyright owner as "Not a Contribution."
+
+      "Contributor" shall mean Licensor and any individual or Legal Entity
+      on behalf of whom a Contribution has been received by Licensor and
+      subsequently incorporated within the Work.
+
+   2. Grant of Copyright License. Subject to the terms and conditions of
+      this License, each Contributor hereby grants to You a perpetual,
+      worldwide, non-exclusive, no-charge, royalty-free, irrevocable
+      copyright license to reproduce, prepare Derivative Works of,
+      publicly display, publicly perform, sublicense, and distribute the
+      Work and such Derivative Works in Source or Object form.
+
+   3. Grant of Patent License. Subject to the terms and conditions of
+      this License, each Contributor hereby grants to You a perpetual,
+      worldwide, non-exclusive, no-charge, royalty-free, irrevocable
+      (except as stated in this section) patent license to make, have made,
+      use, offer to sell, sell, import, and otherwise transfer the Work,
+      where such license applies only to those patent claims licensable
+      by such Contributor that are necessarily infringed by their
+      Contribution(s) alone or by combination of their Contribution(s)
+      with the Work to which such Contribution(s) was submitted. If You
+      institute patent litigation against any entity (including a
+      cross-claim or counterclaim in a lawsuit) alleging that the Work
+      or a Contribution incorporated within the Work constitutes direct
+      or contributory patent infringement, then any patent licenses
+      granted to You under this License for that Work shall terminate
+      as of the date such litigation is filed.
+
+   4. Redistribution. You may reproduce and distribute copies of the
+      Work or Derivative Works thereof in any medium, with or without
+      modifications, and in Source or Object form, provided that You
+      meet the following conditions:
+
+      (a) You must give any other recipients of the Work or
+          Derivative Works a copy of this License; and
+
+      (b) You must cause any modified files to carry prominent notices
+          stating that You changed the files; and
+
+      (c) You must retain, in the Source form of any Derivative Works
+          that You distribute, all copyright, patent, trademark, and
+          attribution notices from the Source form of the Work,
+          excluding those notices that do not pertain to any part of
+          the Derivative Works; and
+
+      (d) If the Work includes a "NOTICE" text file as part of its
+          distribution, then any Derivative Works that You distribute must
+          include a readable copy of the attribution notices contained
+          within such NOTICE file, excluding those notices that do not
+          pertain to any part of the Derivative Works, in at least one
+          of the following places: within a NOTICE text file distributed
+          as part of the Derivative Works; within the Source form or
+          documentation, if provided along with the Derivative Works; or,
+          within a display generated by the Derivative Works, if and
+          wherever such third-party notices normally appear. The contents
+          of the NOTICE file are for informational purposes only and
+          do not modify the License. You may add Your own attribution
+          notices within Derivative Works that You distribute, alongside
+          or as an addendum to the NOTICE text from the Work, provided
+          that such additional attribution notices cannot be construed
+          as modifying the License.
+
+      You may add Your own copyright statement to Your modifications and
+      may provide additional or different license terms and conditions
+      for use, reproduction, or distribution of Your modifications, or
+      for any such Derivative Works as a whole, provided Your use,
+      reproduction, and distribution of the Work otherwise complies with
+      the conditions stated in this License.
+
+   5. Submission of Contributions. Unless You explicitly state otherwise,
+      any Contribution intentionally submitted for inclusion in the Work
+      by You to the Licensor shall be under the terms and conditions of
+      this License, without any additional terms or conditions.
+      Notwithstanding the above, nothing herein shall supersede or modify
+      the terms of any separate license agreement you may have executed
+      with Licensor regarding such Contributions.
+
+   6. Trademarks. This License does not grant permission to use the trade
+      names, trademarks, service marks, or product names of the Licensor,
+      except as required for reasonable and customary use in describing the
+      origin of the Work and reproducing the content of the NOTICE file.
+
+   7. Disclaimer of Warranty. Unless required by applicable law or
+      agreed to in writing, Licensor provides the Work (and each
+      Contributor provides its Contributions) on an "AS IS" BASIS,
+      WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+      implied, including, without limitation, any warranties or conditions
+      of TITLE, NON-INFRINGEMENT, MERCHANTABILITY, or FITNESS FOR A
+      PARTICULAR PURPOSE. You are solely responsible for determining the
+      appropriateness of using or redistributing the Work and assume any
+      risks associated with Your exercise of permissions under this License.
+
+   8. Limitation of Liability. In no event and under no legal theory,
+      whether in tort (including negligence), contract, or otherwise,
+      unless required by applicable law (such as deliberate and grossly
+      negligent acts) or agreed to in writing, shall any Contributor be
+      liable to You for damages, including any direct, indirect, special,
+      incidental, or consequential damages of any character arising as a
+      result of this License or out of the use or inability to use the
+      Work (including but not limited to damages for loss of goodwill,
+      work stoppage, computer failure or malfunction, or any and all
+      other commercial damages or losses), even if such Contributor
+      has been advised of the possibility of such damages.
+
+   9. Accepting Warranty or Additional Liability. While redistributing
+      the Work or Derivative Works thereof, You may choose to offer,
+      and charge a fee for, acceptance of support, warranty, indemnity,
+      or other liability obligations and/or rights consistent with this
+      License. However, in accepting such obligations, You may act only
+      on Your own behalf and on Your sole responsibility, not on behalf
+      of any other Contributor, and only if You agree to indemnify,
+      defend, and hold each Contributor harmless for any liability
+      incurred by, or claims asserted against, such Contributor by reason
+      of your accepting any such warranty or additional liability.
+
+   END OF TERMS AND CONDITIONS
+
+   APPENDIX: How to apply the Apache License to your work.
+
+      To apply the Apache License to your work, attach the following
+      boilerplate notice, with the fields enclosed by brackets "[]"
+      replaced with your own identifying information. (Don't include
+      the brackets!)  The text should be enclosed in the appropriate
+      comment syntax for the file format. We also recommend that a
+      file or class name and description of purpose be included on the
+      same "printed page" as the copyright notice for easier
+      identification within third-party archives.
+
+   Copyright 2019 Jacob Pratt
+
+   Licensed under the Apache License, Version 2.0 (the "License");
+   you may not use this file except in compliance with the License.
+   You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
diff --git a/LICENSE-MIT b/LICENSE-MIT
new file mode 100644
index 0000000..1ddffb9
--- /dev/null
+++ b/LICENSE-MIT
@@ -0,0 +1,19 @@
+Copyright (c) 2019 Jacob Pratt
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.
diff --git a/METADATA b/METADATA
new file mode 100644
index 0000000..32aebc6
--- /dev/null
+++ b/METADATA
@@ -0,0 +1,19 @@
+name: "time-macros-impl"
+description: "Procedural macros for the time crate."
+third_party {
+  url {
+    type: HOMEPAGE
+    value: "https://crates.io/crates/time-macros-impl"
+  }
+  url {
+    type: ARCHIVE
+    value: "https://static.crates.io/crates/time-macros-impl/time-macros-impl-0.1.1.crate"
+  }
+  version: "0.1.1"
+  license_type: NOTICE
+  last_upgrade_date {
+    year: 2020
+    month: 10
+    day: 21
+  }
+}
diff --git a/MODULE_LICENSE_APACHE2 b/MODULE_LICENSE_APACHE2
new file mode 100644
index 0000000..e69de29
--- /dev/null
+++ b/MODULE_LICENSE_APACHE2
diff --git a/OWNERS b/OWNERS
new file mode 100644
index 0000000..46fc303
--- /dev/null
+++ b/OWNERS
@@ -0,0 +1 @@
+include platform/prebuilts/rust:/OWNERS
diff --git a/src/date.rs b/src/date.rs
new file mode 100644
index 0000000..d246579
--- /dev/null
+++ b/src/date.rs
@@ -0,0 +1,92 @@
+use crate::{
+    ext::LitIntExtension,
+    time_crate,
+    time_crate::{days_in_year, days_in_year_month, weeks_in_year},
+};
+use proc_macro2::TokenStream;
+use quote::{quote, ToTokens};
+use syn::{
+    parse::{Parse, ParseStream},
+    Ident, LitInt, Result, Token,
+};
+
+pub(crate) struct Date {
+    year: i32,
+    ordinal: u16,
+}
+
+impl Parse for Date {
+    fn parse(input: ParseStream<'_>) -> Result<Self> {
+        let (year, year_span) = {
+            let year_sign = if input.peek(Token![+]) {
+                input.parse::<Token![+]>()?;
+                1
+            } else if input.peek(Token![-]) {
+                input.parse::<Token![-]>()?;
+                -1
+            } else {
+                1
+            };
+            let year = input.parse::<LitInt>()?;
+            (year_sign * year.value::<i32>()?, year.span())
+        };
+        input.parse::<Token![-]>()?;
+
+        // year-week-day
+        let (year, ordinal) = if input.peek(Ident) {
+            let week = {
+                let week = input.parse::<Ident>()?;
+                let week_str = week.to_string();
+                if week_str.starts_with('W') {
+                    LitInt::new(&week_str[1..], week.span())
+                } else {
+                    return error!(week.span(), "expected week value to start with `W`");
+                }
+            };
+            input.parse::<Token![-]>()?;
+            let day = input.parse::<LitInt>()?;
+
+            week.ensure_in_range(0..=weeks_in_year(year) as isize)?;
+            day.ensure_in_range(1..=7)?;
+
+            time_crate::Date::from_iso_ywd_unchecked(year, week.value()?, day.value()?).as_yo()
+        }
+        // year-month-day
+        else if input.peek2(Token![-]) {
+            let month = input.parse::<LitInt>()?;
+            input.parse::<Token![-]>()?;
+            let day = input.parse::<LitInt>()?;
+
+            month.ensure_in_range(1..=12)?;
+            day.ensure_in_range(1..=days_in_year_month(year, month.value()?) as isize)?;
+
+            time_crate::Date::from_ymd_unchecked(year, month.value()?, day.value()?).as_yo()
+        }
+        // year-ordinal
+        else {
+            let ordinal = input.parse::<LitInt>()?;
+            ordinal.ensure_in_range(1..=days_in_year(year) as isize)?;
+            (year, ordinal.value()?)
+        };
+
+        // TODO(upstream) Swap out the following when dtolnay/syn#748 is
+        // published on crates.io. Be sure to update Cargo.toml for the minimum
+        // version.
+        // LitInt::create(year).using_span(year_span).ensure_in_range(-100_000..=100_000)?;
+        if year < -100_000 || year > 100_000 {
+            return error!(year_span, "value must be in the range -100_000..=100_000");
+        }
+
+        Ok(Self { year, ordinal })
+    }
+}
+
+impl ToTokens for Date {
+    fn to_tokens(&self, tokens: &mut TokenStream) {
+        let Self { year, ordinal } = self;
+
+        tokens.extend(quote! {
+            ::time::internals::Date::from_yo_unchecked(#year, #ordinal)
+        })
+    }
+}
diff --git a/src/ext.rs b/src/ext.rs
new file mode 100644
index 0000000..abdf0b8
--- /dev/null
+++ b/src/ext.rs
@@ -0,0 +1,48 @@
+use proc_macro2::Span;
+#[allow(unused_imports)]
+use standback::prelude::*;
+use std::{
+    fmt::{Debug, Display},
+    ops::RangeBounds,
+    str::FromStr,
+};
+use syn::{LitInt, Result};
+
+pub(crate) trait LitIntExtension {
+    fn create<T: Display>(value: T) -> Self;
+    fn with_span(self, span: Span) -> Self;
+    fn ensure_in_range(&self, range: impl RangeBounds<isize> + Debug) -> Result<()>;
+    fn value<T: FromStr + Display>(&self) -> Result<T>
+    where
+        T::Err: Display;
+}
+
+impl LitIntExtension for LitInt {
+    fn create<T: Display>(value: T) -> Self {
+        Self::new(&value.to_string(), Span::call_site())
+    }
+
+    fn with_span(mut self, span: Span) -> Self {
+        self.set_span(span);
+        self
+    }
+
+    #[allow(unstable_name_collisions)]
+    fn ensure_in_range(&self, range: impl RangeBounds<isize> + Debug) -> Result<()> {
+        if range.contains(&self.value()?) {
+            Ok(())
+        } else {
+            error!(self.span(), "value must be in range {:?}", range)
+        }
+    }
+
+    fn value<T: FromStr + Display>(&self) -> Result<T>
+    where
+        T::Err: Display,
+    {
+        match self.base10_parse() {
+            Ok(value) => Ok(value),
+            Err(e) => error!(self.span(), "{}", e),
+        }
+    }
+}
diff --git a/src/lib.rs b/src/lib.rs
new file mode 100644
index 0000000..ce3f4d2
--- /dev/null
+++ b/src/lib.rs
@@ -0,0 +1,95 @@
+#![forbid(unsafe_code)]
+#![deny(
+    anonymous_parameters,
+    rust_2018_idioms,
+    trivial_casts,
+    trivial_numeric_casts,
+    unreachable_pub,
+    const_err,
+    illegal_floating_point_literal_pattern,
+    late_bound_lifetime_arguments,
+    path_statements,
+    patterns_in_fns_without_body,
+    clippy::all
+)]
+#![warn(
+    unused_extern_crates,
+    missing_copy_implementations,
+    missing_debug_implementations,
+    single_use_lifetimes,
+    unused_qualifications,
+    variant_size_differences,
+    clippy::pedantic,
+    clippy::nursery,
+    clippy::decimal_literal_representation,
+    clippy::get_unwrap,
+    clippy::option_unwrap_used,
+    clippy::print_stdout,
+    clippy::result_unwrap_used
+)]
+#![allow(
+    clippy::inline_always,
+    clippy::cast_possible_wrap,
+    clippy::cast_lossless,
+    clippy::module_name_repetitions,
+    clippy::must_use_candidate,
+    clippy::use_self, // Not supported in some situations in older compilers.
+)]
+
+// This is required on rustc < 1.42.0.
+#[allow(unused_extern_crates)]
+extern crate proc_macro;
+
+macro_rules! error {
+    ($message:literal) => {
+        error!(::proc_macro2::Span::call_site(), $message)
+    };
+
+    ($span:expr, $message:literal) => {
+        Err(::syn::Error::new($span, $message))
+    };
+
+    ($span:expr, $($args:expr),+) => {
+        Err(::syn::Error::new($span, format!($($args),+)))
+    };
+}
+
+mod kw {
+    use syn::custom_keyword;
+    custom_keyword!(am);
+    custom_keyword!(pm);
+    custom_keyword!(AM);
+    custom_keyword!(PM);
+    custom_keyword!(utc);
+    custom_keyword!(UTC);
+}
+
+mod date;
+mod ext;
+mod offset;
+mod time;
+mod time_crate;
+
+use date::Date;
+use offset::Offset;
+use proc_macro_hack::proc_macro_hack;
+use quote::ToTokens;
+use syn::parse_macro_input;
+use time::Time;
+
+macro_rules! impl_macros {
+    ($($name:ident : $type:ty),* $(,)?) => {
+        $(
+            #[proc_macro_hack]
+            pub fn $name(input: proc_macro::TokenStream) -> proc_macro::TokenStream {
+                parse_macro_input!(input as $type).to_token_stream().into()
+            }
+        )*
+    };
+}
+
+impl_macros! {
+    time: Time,
+    offset: Offset,
+    date: Date,
+}
diff --git a/src/offset.rs b/src/offset.rs
new file mode 100644
index 0000000..86fe836
--- /dev/null
+++ b/src/offset.rs
@@ -0,0 +1,80 @@
+use crate::{
+    ext::LitIntExtension,
+    kw::{utc, UTC},
+};
+use proc_macro2::TokenStream;
+use quote::{quote, ToTokens};
+use syn::{
+    parse::{Parse, ParseStream},
+    LitInt, Result, Token,
+};
+
+#[repr(i8)]
+enum Direction {
+    East = 1,
+    West = -1,
+}
+
+pub(crate) struct Offset {
+    pub(crate) offset: i32,
+}
+
+impl Parse for Offset {
+    fn parse(input: ParseStream<'_>) -> Result<Self> {
+        if input.peek(utc) {
+            input.parse::<utc>()?;
+            return Ok(Self { offset: 0 });
+        }
+        if input.peek(UTC) {
+            input.parse::<UTC>()?;
+            return Ok(Self { offset: 0 });
+        }
+
+        let direction = if input.peek(Token![+]) {
+            input.parse::<Token![+]>()?;
+            Direction::East
+        } else if input.peek(Token![-]) {
+            input.parse::<Token![-]>()?;
+            Direction::West
+        } else {
+            return error!("offset must have an explicit sign");
+        };
+
+        let hour = input.parse::<LitInt>()?;
+
+        // Minutes are optional, defaulting to zero.
+        let minute = if input.peek(Token![:]) {
+            input.parse::<Token![:]>()?;
+            input.parse::<LitInt>()?
+        } else {
+            LitInt::create(0)
+        };
+
+        // Seconds are optional, defaulting to zero.
+        let second = if input.peek(Token![:]) {
+            input.parse::<Token![:]>()?;
+            input.parse::<LitInt>()?
+        } else {
+            LitInt::create(0)
+        };
+
+        // Ensure none of the components are out of range.
+        hour.ensure_in_range(0..24)?;
+        minute.ensure_in_range(0..60)?;
+        second.ensure_in_range(0..60)?;
+
+        let offset = direction as i32
+            * (hour.value::<i32>()? * 3_600
+                + minute.value::<i32>()? * 60
+                + second.value::<i32>()?);
+
+        Ok(Self { offset })
+    }
+}
+
+impl ToTokens for Offset {
+    fn to_tokens(&self, tokens: &mut TokenStream) {
+        let Self { offset } = self;
+        tokens.extend(quote! { ::time::UtcOffset::seconds(#offset) });
+    }
+}
diff --git a/src/time.rs b/src/time.rs
new file mode 100644
index 0000000..b03f21d
--- /dev/null
+++ b/src/time.rs
@@ -0,0 +1,133 @@
+use crate::ext::LitIntExtension;
+use proc_macro2::TokenStream;
+use quote::{quote, ToTokens};
+use syn::{
+    parse::{Parse, ParseStream},
+    LitFloat, LitInt, Result, Token,
+};
+
+#[derive(PartialEq)]
+enum AmPm {
+    Am,
+    Pm,
+}
+
+impl Parse for AmPm {
+    fn parse(input: ParseStream<'_>) -> Result<Self> {
+        use crate::kw::{am, pm, AM, PM};
+        if input.peek(am) {
+            input.parse::<am>()?;
+            Ok(AmPm::Am)
+        } else if input.peek(AM) {
+            input.parse::<AM>()?;
+            Ok(AmPm::Am)
+        } else if input.peek(pm) {
+            input.parse::<pm>()?;
+            Ok(AmPm::Pm)
+        } else if input.peek(PM) {
+            input.parse::<PM>()?;
+            Ok(AmPm::Pm)
+        } else {
+            error!("expected am or pm")
+        }
+    }
+}
+
+pub(crate) struct Time {
+    pub(crate) hour: LitInt,
+    pub(crate) minute: LitInt,
+    pub(crate) second: LitInt,
+    pub(crate) nanosecond: LitInt,
+}
+
+impl Parse for Time {
+    fn parse(input: ParseStream<'_>) -> Result<Self> {
+        let mut hour = input.parse::<LitInt>()?;
+        input.parse::<Token![:]>()?;
+        let minute = input.parse::<LitInt>()?;
+
+        // Seconds and nanoseconds are optional, defaulting to zero.
+        let (second, nanosecond) = if input.peek(Token![:]) {
+            input.parse::<Token![:]>()?;
+
+            if input.peek(LitFloat) {
+                let float = input.parse::<LitFloat>()?;
+
+                // Temporary value to satisfy the compiler.
+                let float_str = float.to_string();
+                let parts: Vec<_> = float_str.splitn(2, '.').collect();
+
+                let seconds = LitInt::new(parts[0], float.span());
+                let nanoseconds = {
+                    // Prepend a zero to avoid having an empty string.
+                    // Strip the suffix to avoid syn thinking it's a float.
+                    let raw_padded = format!("0{}", parts[1].trim_end_matches(float.suffix()));
+
+                    // Take an extra digit due to the padding.
+                    let digits: String = raw_padded
+                        .chars()
+                        .filter(char::is_ascii_digit)
+                        .take(10)
+                        .collect();
+
+                    // Scale the value based on how many digits were provided.
+                    #[allow(clippy::cast_possible_truncation)]
+                    let value = LitInt::new(&digits, float.span()).base10_parse::<usize>()?
+                        * 10_usize.pow(10 - digits.len() as u32);
+
+                    LitInt::create(value).with_span(float.span())
+                };
+
+                (seconds, nanoseconds)
+            } else {
+                (input.parse::<LitInt>()?, LitInt::create(0))
+            }
+        } else {
+            (LitInt::create(0), LitInt::create(0))
+        };
+
+        let am_pm = input.parse::<AmPm>().ok();
+
+        // Ensure none of the components are out of range.
+        match am_pm {
+            Some(am_pm) => {
+                hour.ensure_in_range(1..=12)?;
+                // Adjust the hour if necessary.
+                hour = match (hour.value()?, am_pm) {
+                    (12, AmPm::Am) => LitInt::create(0).with_span(hour.span()),
+                    (value, AmPm::Pm) if value != 12 => {
+                        LitInt::create(value + 12).with_span(hour.span())
+                    }
+                    _ => hour,
+                }
+            }
+            None => hour.ensure_in_range(0..24)?,
+        }
+        minute.ensure_in_range(0..60)?;
+        second.ensure_in_range(0..60)?;
+        // This likely isn't necessary, but it can't hurt.
+        nanosecond.ensure_in_range(0..1_000_000_000)?;
+
+        Ok(Self {
+            hour,
+            minute,
+            second,
+            nanosecond,
+        })
+    }
+}
+
+impl ToTokens for Time {
+    fn to_tokens(&self, tokens: &mut TokenStream) {
+        let Self {
+            hour,
+            minute,
+            second,
+            nanosecond,
+        } = self;
+
+        tokens.extend(quote! {
+            ::time::internals::Time::from_hms_nanos_unchecked(#hour, #minute, #second, #nanosecond)
+        });
+    }
+}
diff --git a/src/time_crate/date.rs b/src/time_crate/date.rs
new file mode 100644
index 0000000..981630e
--- /dev/null
+++ b/src/time_crate/date.rs
@@ -0,0 +1,147 @@
+use super::Weekday::{self, Friday, Monday, Saturday, Sunday, Thursday, Tuesday, Wednesday};
+#[allow(unused_imports)]
+use standback::prelude::*;
+
+fn is_leap_year(year: i32) -> bool {
+    (year % 4 == 0) && ((year % 100 != 0) || (year % 400 == 0))
+}
+
+pub(crate) fn days_in_year(year: i32) -> u16 {
+    365 + is_leap_year(year) as u16
+}
+
+/// The number of days in a month in both common and leap years.
+const DAYS_IN_MONTH_COMMON_LEAP: [[u16; 12]; 2] = [
+    [31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31],
+    [31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31],
+];
+
+#[allow(clippy::cast_possible_truncation)]
+pub(crate) fn days_in_year_month(year: i32, month: u8) -> u8 {
+    DAYS_IN_MONTH_COMMON_LEAP[is_leap_year(year) as usize][month as usize - 1] as u8
+}
+
+pub(crate) fn weeks_in_year(year: i32) -> u8 {
+    let weekday = Date { year, ordinal: 1 }.weekday();
+
+    if (weekday == Thursday) || (weekday == Wednesday && is_leap_year(year)) {
+        53
+    } else {
+        52
+    }
+}
+
+pub(crate) struct Date {
+    year: i32,
+    pub(crate) ordinal: u16,
+}
+
+impl Date {
+    pub(crate) const fn as_yo(&self) -> (i32, u16) {
+        (self.year, self.ordinal)
+    }
+
+    pub(crate) fn month_day(&self) -> (u8, u8) {
+        const CUMULATIVE_DAYS_IN_MONTH_COMMON_LEAP: [[u16; 11]; 2] = [
+            [31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334],
+            [31, 60, 91, 121, 152, 182, 213, 244, 274, 305, 335],
+        ];
+
+        let days = CUMULATIVE_DAYS_IN_MONTH_COMMON_LEAP[is_leap_year(self.year) as usize];
+        let ordinal = self.ordinal;
+
+        #[allow(clippy::cast_possible_truncation)]
+        {
+            if ordinal > days[10] {
+                (12, (ordinal - days[10]) as u8)
+            } else if ordinal > days[9] {
+                (11, (ordinal - days[9]) as u8)
+            } else if ordinal > days[8] {
+                (10, (ordinal - days[8]) as u8)
+            } else if ordinal > days[7] {
+                (9, (ordinal - days[7]) as u8)
+            } else if ordinal > days[6] {
+                (8, (ordinal - days[6]) as u8)
+            } else if ordinal > days[5] {
+                (7, (ordinal - days[5]) as u8)
+            } else if ordinal > days[4] {
+                (6, (ordinal - days[4]) as u8)
+            } else if ordinal > days[3] {
+                (5, (ordinal - days[3]) as u8)
+            } else if ordinal > days[2] {
+                (4, (ordinal - days[2]) as u8)
+            } else if ordinal > days[1] {
+                (3, (ordinal - days[1]) as u8)
+            } else if ordinal > days[0] {
+                (2, (ordinal - days[0]) as u8)
+            } else {
+                (1, ordinal as u8)
+            }
+        }
+    }
+
+    #[allow(unstable_name_collisions)]
+    pub(crate) fn weekday(&self) -> Weekday {
+        let (month, day) = self.month_day();
+
+        let (month, adjusted_year) = if month < 3 {
+            (month + 12, self.year - 1)
+        } else {
+            (month, self.year)
+        };
+
+        match (day as i32 + (13 * (month as i32 + 1)) / 5 + adjusted_year + adjusted_year / 4
+            - adjusted_year / 100
+            + adjusted_year / 400)
+            .rem_euclid(7)
+        {
+            0 => Saturday,
+            1 => Sunday,
+            2 => Monday,
+            3 => Tuesday,
+            4 => Wednesday,
+            5 => Thursday,
+            6 => Friday,
+            _ => unreachable!("A value mod 7 is always in the range 0..7"),
+        }
+    }
+
+    pub(crate) fn from_iso_ywd_unchecked(year: i32, week: u8, iso_weekday_number: u8) -> Date {
+        let ordinal = week as u16 * 7 + iso_weekday_number as u16
+            - (Self::from_yo_unchecked(year, 4)
+                .weekday()
+                .iso_weekday_number() as u16
+                + 3);
+
+        if ordinal < 1 {
+            return Self::from_yo_unchecked(year - 1, ordinal + days_in_year(year - 1));
+        }
+
+        let days_in_cur_year = days_in_year(year);
+        if ordinal > days_in_cur_year {
+            Self::from_yo_unchecked(year + 1, ordinal - days_in_cur_year)
+        } else {
+            Self::from_yo_unchecked(year, ordinal)
+        }
+    }
+
+    pub(crate) fn from_ymd_unchecked(year: i32, month: u8, day: u8) -> Date {
+        /// Cumulative days through the beginning of a month in both common and
+        /// leap years.
+        const DAYS_CUMULATIVE_COMMON_LEAP: [[u16; 12]; 2] = [
+            [0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334],
+            [0, 31, 60, 91, 121, 152, 182, 213, 244, 274, 305, 335],
+        ];
+
+        let ordinal = DAYS_CUMULATIVE_COMMON_LEAP[is_leap_year(year) as usize][month as usize - 1];
+
+        Date {
+            year,
+            ordinal: ordinal + day as u16,
+        }
+    }
+
+    pub(crate) const fn from_yo_unchecked(year: i32, ordinal: u16) -> Date {
+        Date { year, ordinal }
+    }
+}
diff --git a/src/time_crate/mod.rs b/src/time_crate/mod.rs
new file mode 100644
index 0000000..a26cd11
--- /dev/null
+++ b/src/time_crate/mod.rs
@@ -0,0 +1,24 @@
+// Because time (indirectly) depends on this crate, we can't depend on time
+// here. As such, we need to copy the functions over. If/when proc macros can be
+// declared in the same crate, this will no longer be necessary.
+
+mod date;
+
+pub(crate) use date::{days_in_year, days_in_year_month, weeks_in_year, Date};
+
+#[derive(PartialEq)]
+pub(crate) enum Weekday {
+    Monday,
+    Tuesday,
+    Wednesday,
+    Thursday,
+    Friday,
+    Saturday,
+    Sunday,
+}
+
+impl Weekday {
+    pub(crate) const fn iso_weekday_number(self) -> u8 {
+        self as u8 + 1
+    }
+}