diff --git a/Android.bp b/Android.bp
index 35ea8ad..ddb4de6 100644
--- a/Android.bp
+++ b/Android.bp
@@ -73,6 +73,9 @@
         "src/**/deskclock/data/TimerNotificationBuilder.java",
         "src/**/deskclock/data/TimerStringFormatter.java",
         "src/**/deskclock/data/TimeZones.java",
+        "src/**/deskclock/data/Weekdays.java",
+        "src/**/deskclock/data/WidgetDAO.java",
+        "src/**/deskclock/data/WidgetModel.java",
         "src/**/deskclock/events/*.java",
         "src/**/deskclock/provider/*.java",
         "src/**/deskclock/settings/*.java",
diff --git a/src/com/android/deskclock/data/Weekdays.kt b/src/com/android/deskclock/data/Weekdays.kt
new file mode 100644
index 0000000..3f792fc
--- /dev/null
+++ b/src/com/android/deskclock/data/Weekdays.kt
@@ -0,0 +1,307 @@
+/*
+ * Copyright (C) 2020 The Android Open Source Project
+ *
+ * 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.
+ */
+
+package com.android.deskclock.data
+
+import android.content.Context
+import androidx.annotation.VisibleForTesting
+
+import com.android.deskclock.R
+
+import java.text.DateFormatSymbols
+import java.util.Calendar
+
+/**
+ * This class is responsible for encoding a weekly repeat cycle in a [bitset][.getBits]. It
+ * also converts between those bits and the [Calendar.DAY_OF_WEEK] values for easier mutation
+ * and querying.
+ */
+class Weekdays private constructor(bits: Int) {
+    /**
+     * The preferred starting day of the week can differ by locale. This enumerated value is used to
+     * describe the preferred ordering.
+     */
+    enum class Order(vararg calendarDays: Int) {
+        SAT_TO_FRI(Calendar.SATURDAY, Calendar.SUNDAY, Calendar.MONDAY,
+                Calendar.TUESDAY, Calendar.WEDNESDAY, Calendar.THURSDAY, Calendar.FRIDAY),
+        SUN_TO_SAT(Calendar.SUNDAY, Calendar.MONDAY, Calendar.TUESDAY, Calendar.WEDNESDAY,
+                Calendar.THURSDAY, Calendar.FRIDAY, Calendar.SATURDAY),
+        MON_TO_SUN(Calendar.MONDAY, Calendar.TUESDAY, Calendar.WEDNESDAY, Calendar.THURSDAY,
+                Calendar.FRIDAY, Calendar.SATURDAY, Calendar.SUNDAY);
+
+        val calendarDays: List<Int> = calendarDays.asList()
+    }
+
+    companion object {
+        /** All valid bits set.  */
+        private const val ALL_DAYS = 0x7F
+
+        /** An instance with all weekdays in the weekly repeat cycle.  */
+        @JvmField
+        val ALL = fromBits(ALL_DAYS)
+
+        /** An instance with no weekdays in the weekly repeat cycle.  */
+        @JvmField
+        val NONE = fromBits(0)
+
+        /** Maps calendar weekdays to the bit masks that represent them in this class.  */
+        private val sCalendarDayToBit: Map<Int, Int>
+
+        init {
+            val map: MutableMap<Int, Int> = mutableMapOf()
+            map[Calendar.MONDAY] = 0x01
+            map[Calendar.TUESDAY] = 0x02
+            map[Calendar.WEDNESDAY] = 0x04
+            map[Calendar.THURSDAY] = 0x08
+            map[Calendar.FRIDAY] = 0x10
+            map[Calendar.SATURDAY] = 0x20
+            map[Calendar.SUNDAY] = 0x40
+            sCalendarDayToBit = map
+        }
+
+        /**
+         * @param bits [bits][.getBits] representing the encoded weekly repeat schedule
+         * @return a Weekdays instance representing the same repeat schedule as the `bits`
+         */
+        @JvmStatic
+        fun fromBits(bits: Int): Weekdays {
+            return Weekdays(bits)
+        }
+
+        /**
+         * @param calendarDays an array containing any or all of the following values
+         *
+         *  * [Calendar.SUNDAY]
+         *  * [Calendar.MONDAY]
+         *  * [Calendar.TUESDAY]
+         *  * [Calendar.WEDNESDAY]
+         *  * [Calendar.THURSDAY]
+         *  * [Calendar.FRIDAY]
+         *  * [Calendar.SATURDAY]
+         *
+         * @return a Weekdays instance representing the given `calendarDays`
+         */
+        @JvmStatic
+        fun fromCalendarDays(vararg calendarDays: Int): Weekdays {
+            var bits = 0
+            for (calendarDay in calendarDays) {
+                val bit = sCalendarDayToBit[calendarDay]
+                if (bit != null) {
+                    bits = bits or bit
+                }
+            }
+            return Weekdays(bits)
+        }
+    }
+
+    /** An encoded form of a weekly repeat schedule.  */
+    val bits: Int = ALL_DAYS and bits
+
+    /**
+     * @param calendarDay any of the following values
+     *
+     *  * [Calendar.SUNDAY]
+     *  * [Calendar.MONDAY]
+     *  * [Calendar.TUESDAY]
+     *  * [Calendar.WEDNESDAY]
+     *  * [Calendar.THURSDAY]
+     *  * [Calendar.FRIDAY]
+     *  * [Calendar.SATURDAY]
+     *
+     * @param on `true` if the `calendarDay` is on; `false` otherwise
+     * @return a WeekDays instance with the `calendarDay` mutated
+     */
+    fun setBit(calendarDay: Int, on: Boolean): Weekdays {
+        val bit = sCalendarDayToBit[calendarDay] ?: return this
+        return Weekdays(if (on) bits or bit else bits and bit.inv())
+    }
+
+    /**
+     * @param calendarDay any of the following values
+     *
+     *  * [Calendar.SUNDAY]
+     *  * [Calendar.MONDAY]
+     *  * [Calendar.TUESDAY]
+     *  * [Calendar.WEDNESDAY]
+     *  * [Calendar.THURSDAY]
+     *  * [Calendar.FRIDAY]
+     *  * [Calendar.SATURDAY]
+     *
+     * @return `true` if the given `calendarDay`
+     */
+    fun isBitOn(calendarDay: Int): Boolean {
+        val bit = sCalendarDayToBit[calendarDay]
+                ?: throw IllegalArgumentException("$calendarDay is not a valid weekday")
+        return bits and bit > 0
+    }
+
+    /**
+     * @return `true` iff at least one weekday is enabled in the repeat schedule
+     */
+    val isRepeating: Boolean
+        get() = bits != 0
+
+    /**
+     * Note: only the day-of-week is read from the `time`. The time fields
+     * are not considered in this computation.
+     *
+     * @param time a timestamp relative to which the answer is given
+     * @return the number of days between the given `time` and the previous enabled weekday
+     * which is always between 1 and 7 inclusive; `-1` if no weekdays are enabled
+     */
+    fun getDistanceToPreviousDay(time: Calendar): Int {
+        var calendarDay = time[Calendar.DAY_OF_WEEK]
+        for (count in 1..7) {
+            calendarDay--
+            if (calendarDay < Calendar.SUNDAY) {
+                calendarDay = Calendar.SATURDAY
+            }
+            if (isBitOn(calendarDay)) {
+                return count
+            }
+        }
+
+        return -1
+    }
+
+    /**
+     * Note: only the day-of-week is read from the `time`. The time fields
+     * are not considered in this computation.
+     *
+     * @param time a timestamp relative to which the answer is given
+     * @return the number of days between the given `time` and the next enabled weekday which
+     * is always between 0 and 6 inclusive; `-1` if no weekdays are enabled
+     */
+    fun getDistanceToNextDay(time: Calendar): Int {
+        var calendarDay = time[Calendar.DAY_OF_WEEK]
+        for (count in 0..6) {
+            if (isBitOn(calendarDay)) {
+                return count
+            }
+
+            calendarDay++
+            if (calendarDay > Calendar.SATURDAY) {
+                calendarDay = Calendar.SUNDAY
+            }
+        }
+
+        return -1
+    }
+
+    override fun equals(other: Any?): Boolean {
+        if (this === other) return true
+        if (other == null || javaClass != other.javaClass) return false
+
+        val weekdays = other as Weekdays
+        return bits == weekdays.bits
+    }
+
+    override fun hashCode(): Int {
+        return bits
+    }
+
+    override fun toString(): String {
+        val builder = StringBuilder(19)
+        builder.append("[")
+        if (isBitOn(Calendar.MONDAY)) {
+            builder.append(if (builder.length > 1) " M" else "M")
+        }
+        if (isBitOn(Calendar.TUESDAY)) {
+            builder.append(if (builder.length > 1) " T" else "T")
+        }
+        if (isBitOn(Calendar.WEDNESDAY)) {
+            builder.append(if (builder.length > 1) " W" else "W")
+        }
+        if (isBitOn(Calendar.THURSDAY)) {
+            builder.append(if (builder.length > 1) " Th" else "Th")
+        }
+        if (isBitOn(Calendar.FRIDAY)) {
+            builder.append(if (builder.length > 1) " F" else "F")
+        }
+        if (isBitOn(Calendar.SATURDAY)) {
+            builder.append(if (builder.length > 1) " Sa" else "Sa")
+        }
+        if (isBitOn(Calendar.SUNDAY)) {
+            builder.append(if (builder.length > 1) " Su" else "Su")
+        }
+        builder.append("]")
+        return builder.toString()
+    }
+
+    /**
+     * @param context for accessing resources
+     * @param order the order in which to present the weekdays
+     * @return the enabled weekdays in the given `order`
+     */
+    fun toString(context: Context, order: Order): String {
+        return toString(context, order, false /* forceLongNames */)
+    }
+
+    /**
+     * @param context for accessing resources
+     * @param order the order in which to present the weekdays
+     * @return the enabled weekdays in the given `order` in a manner that
+     * is most appropriate for talk-back
+     */
+    fun toAccessibilityString(context: Context, order: Order): String {
+        return toString(context, order, true /* forceLongNames */)
+    }
+
+    @get:VisibleForTesting
+    val count: Int
+        get() {
+            var count = 0
+            for (calendarDay in Calendar.SUNDAY..Calendar.SATURDAY) {
+                if (isBitOn(calendarDay)) {
+                    count++
+                }
+            }
+            return count
+        }
+
+    /**
+     * @param context for accessing resources
+     * @param order the order in which to present the weekdays
+     * @param forceLongNames if `true` the un-abbreviated weekdays are used
+     * @return the enabled weekdays in the given `order`
+     */
+    private fun toString(context: Context, order: Order, forceLongNames: Boolean): String {
+        if (!isRepeating) {
+            return ""
+        }
+
+        if (bits == ALL_DAYS) {
+            return context.getString(R.string.every_day)
+        }
+
+        val longNames = forceLongNames || count <= 1
+        val dfs = DateFormatSymbols()
+        val weekdays = if (longNames) dfs.weekdays else dfs.shortWeekdays
+
+        val separator: String = context.getString(R.string.day_concat)
+
+        val builder = StringBuilder(40)
+        for (calendarDay in order.calendarDays) {
+            if (isBitOn(calendarDay)) {
+                if (builder.isNotEmpty()) {
+                    builder.append(separator)
+                }
+                builder.append(weekdays[calendarDay])
+            }
+        }
+        return builder.toString()
+    }
+}
\ No newline at end of file
diff --git a/src/com/android/deskclock/data/WidgetDAO.kt b/src/com/android/deskclock/data/WidgetDAO.kt
new file mode 100644
index 0000000..3259971
--- /dev/null
+++ b/src/com/android/deskclock/data/WidgetDAO.kt
@@ -0,0 +1,48 @@
+/*
+ * Copyright (C) 2020 The Android Open Source Project
+ *
+ * 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.
+ */
+
+package com.android.deskclock.data
+
+import android.content.SharedPreferences
+
+/**
+ * This class encapsulates the transfer of data between widget objects and their permanent storage
+ * in [SharedPreferences].
+ */
+internal object WidgetDAO {
+    /** Suffix for a key to a preference that stores the instance count for a given widget type.  */
+    private const val WIDGET_COUNT = "_widget_count"
+
+    /**
+     * @param widgetProviderClass indicates the type of widget being counted
+     * @param count the number of widgets of the given type
+     * @return the delta between the new count and the old count
+     */
+    fun updateWidgetCount(
+        prefs: SharedPreferences,
+        widgetProviderClass: Class<*>,
+        count: Int
+    ): Int {
+        val key = widgetProviderClass.simpleName + WIDGET_COUNT
+        val oldCount: Int = prefs.getInt(key, 0)
+        if (count == 0) {
+            prefs.edit().remove(key).apply()
+        } else {
+            prefs.edit().putInt(key, count).apply()
+        }
+        return count - oldCount
+    }
+}
\ No newline at end of file
diff --git a/src/com/android/deskclock/data/WidgetModel.kt b/src/com/android/deskclock/data/WidgetModel.kt
new file mode 100644
index 0000000..b63014f
--- /dev/null
+++ b/src/com/android/deskclock/data/WidgetModel.kt
@@ -0,0 +1,45 @@
+/*
+ * Copyright (C) 2020 The Android Open Source Project
+ *
+ * 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.
+ */
+
+package com.android.deskclock.data
+
+import android.content.SharedPreferences
+import androidx.annotation.StringRes
+
+import com.android.deskclock.R
+import com.android.deskclock.events.Events
+
+/**
+ * All widget data is accessed via this model.
+ */
+internal class WidgetModel(private val mPrefs: SharedPreferences) {
+    /**
+     * @param widgetClass indicates the type of widget being counted
+     * @param count the number of widgets of the given type
+     * @param eventCategoryId identifies the category of event to send
+     */
+    fun updateWidgetCount(widgetClass: Class<*>, count: Int, @StringRes eventCategoryId: Int) {
+        var delta = WidgetDAO.updateWidgetCount(mPrefs, widgetClass, count)
+        while (delta > 0) {
+            Events.sendEvent(eventCategoryId, R.string.action_create, 0)
+            delta--
+        }
+        while (delta < 0) {
+            Events.sendEvent(eventCategoryId, R.string.action_delete, 0)
+            delta++
+        }
+    }
+}
\ No newline at end of file