diff --git a/build.gradle b/build.gradle
index 453088d5..9e223540 100644
--- a/build.gradle
+++ b/build.gradle
@@ -1,20 +1,20 @@
 buildscript {
     ext.versions = [
-            'min_sdk_library'     : 15,
+            'min_sdk_library'     : 21,
             'min_sdk_sample'      : 21,
             'target_sdk'          : 28,
             'compile_sdk'         : 28,
             'version_code'        : 1,
             'version_name'        : '0.3.1',
             'kotlin_lang'         : '1.3.72',
+            'desugar_jdk_libs'    : '1.0.5',
             'material_library'    : '1.2.0-beta01',
-            'androidx_appcompat'  : '1.2.0-beta01',
+            'androidx_appcompat'  : '1.2.0-rc01',
             'androidx_legacy'     : '1.0.0',
-            'androidx_core_ktx'   : '1.3.0-beta01',
+            'androidx_core_ktx'   : '1.3.0',
             'constraint_layout'   : '2.0.0-beta6',
             'cardview'            : '1.0.0',
-            'recyclerview'        : '1.1.0',
-            'threetenabp'         : '1.2.4',
+            'recyclerview'        : '1.2.0-alpha03',
             'junit'               : '4.12',
             'espresso'            : '3.2.0',
             'androidx_test_runner': '1.2.0',
diff --git a/library/build.gradle b/library/build.gradle
index 15c62315..d1518d20 100644
--- a/library/build.gradle
+++ b/library/build.gradle
@@ -21,6 +21,7 @@ android {
         }
     }
     compileOptions {
+        coreLibraryDesugaringEnabled true
         sourceCompatibility = 1.8
         targetCompatibility = 1.8
     }
@@ -32,12 +33,10 @@ android {
 
 dependencies {
     implementation fileTree(dir: 'libs', include: ['*.jar'])
+    coreLibraryDesugaring "com.android.tools:desugar_jdk_libs:$versions.desugar_jdk_libs"
     implementation "org.jetbrains.kotlin:kotlin-stdlib-jdk8:$versions.kotlin_lang"
     implementation "androidx.core:core-ktx:$versions.androidx_core_ktx"
 
-    // Expose ThreeTenABP so library users can use it directly.
-    api "com.jakewharton.threetenabp:threetenabp:$versions.threetenabp"
-
     // Expose RecyclerView which is CalendarView's superclass to
     // prevent a compile error when using the library in a project:
     // Error: Supertypes of the following classes cannot be resolved.
@@ -51,10 +50,5 @@ dependencies {
     api "androidx.recyclerview:recyclerview:$versions.recyclerview"
 
     testImplementation "junit:junit:$versions.junit"
-    testImplementation('org.threeten:threetenbp:1.4.4') {
-        // Use threetenBP library for tests as context will
-        // not be available to initialise threetenABP
-        exclude group: 'com.jakewharton.threetenabp', module: 'threetenabp'
-    }
 }
 
diff --git a/library/src/main/java/com/kizitonwose/calendarview/CalendarView.kt b/library/src/main/java/com/kizitonwose/calendarview/CalendarView.kt
index cd98a8b8..fe573f78 100644
--- a/library/src/main/java/com/kizitonwose/calendarview/CalendarView.kt
+++ b/library/src/main/java/com/kizitonwose/calendarview/CalendarView.kt
@@ -9,9 +9,9 @@ import androidx.recyclerview.widget.DiffUtil
 import androidx.recyclerview.widget.RecyclerView
 import com.kizitonwose.calendarview.model.*
 import com.kizitonwose.calendarview.ui.*
-import org.threeten.bp.DayOfWeek
-import org.threeten.bp.LocalDate
-import org.threeten.bp.YearMonth
+import java.time.DayOfWeek
+import java.time.LocalDate
+import java.time.YearMonth
 
 open class CalendarView : RecyclerView {
 
diff --git a/library/src/main/java/com/kizitonwose/calendarview/model/CalendarDay.kt b/library/src/main/java/com/kizitonwose/calendarview/model/CalendarDay.kt
index e00aedc3..6e57ae14 100644
--- a/library/src/main/java/com/kizitonwose/calendarview/model/CalendarDay.kt
+++ b/library/src/main/java/com/kizitonwose/calendarview/model/CalendarDay.kt
@@ -3,10 +3,9 @@ package com.kizitonwose.calendarview.model
 import com.kizitonwose.calendarview.utils.next
 import com.kizitonwose.calendarview.utils.previous
 import com.kizitonwose.calendarview.utils.yearMonth
-import org.threeten.bp.LocalDate
-import org.threeten.bp.YearMonth
 import java.io.Serializable
-
+import java.time.LocalDate
+import java.time.YearMonth
 data class CalendarDay internal constructor(val date: LocalDate, val owner: DayOwner) :
     Comparable<CalendarDay>, Serializable {
 
diff --git a/library/src/main/java/com/kizitonwose/calendarview/model/CalendarMonth.kt b/library/src/main/java/com/kizitonwose/calendarview/model/CalendarMonth.kt
index b29ca223..8fd9a199 100644
--- a/library/src/main/java/com/kizitonwose/calendarview/model/CalendarMonth.kt
+++ b/library/src/main/java/com/kizitonwose/calendarview/model/CalendarMonth.kt
@@ -1,7 +1,7 @@
 package com.kizitonwose.calendarview.model
 
-import org.threeten.bp.YearMonth
 import java.io.Serializable
+import java.time.YearMonth
 
 data class CalendarMonth(
     val yearMonth: YearMonth,
diff --git a/library/src/main/java/com/kizitonwose/calendarview/model/MonthConfig.kt b/library/src/main/java/com/kizitonwose/calendarview/model/MonthConfig.kt
index f0e47cb3..f312af51 100644
--- a/library/src/main/java/com/kizitonwose/calendarview/model/MonthConfig.kt
+++ b/library/src/main/java/com/kizitonwose/calendarview/model/MonthConfig.kt
@@ -1,10 +1,10 @@
 package com.kizitonwose.calendarview.model
 
 import com.kizitonwose.calendarview.utils.next
-import org.threeten.bp.DayOfWeek
-import org.threeten.bp.LocalDate
-import org.threeten.bp.YearMonth
-import org.threeten.bp.temporal.WeekFields
+import java.time.DayOfWeek
+import java.time.LocalDate
+import java.time.YearMonth
+import java.time.temporal.WeekFields
 
 internal data class MonthConfig(
     val outDateStyle: OutDateStyle,
diff --git a/library/src/main/java/com/kizitonwose/calendarview/ui/CalendarAdapter.kt b/library/src/main/java/com/kizitonwose/calendarview/ui/CalendarAdapter.kt
index a9c2c65f..5efb41f7 100644
--- a/library/src/main/java/com/kizitonwose/calendarview/ui/CalendarAdapter.kt
+++ b/library/src/main/java/com/kizitonwose/calendarview/ui/CalendarAdapter.kt
@@ -16,8 +16,8 @@ import com.kizitonwose.calendarview.model.*
 import com.kizitonwose.calendarview.utils.NO_INDEX
 import com.kizitonwose.calendarview.utils.inflate
 import com.kizitonwose.calendarview.utils.orZero
-import org.threeten.bp.LocalDate
-import org.threeten.bp.YearMonth
+import java.time.LocalDate
+import java.time.YearMonth
 
 internal typealias LP = ViewGroup.LayoutParams
 
diff --git a/library/src/main/java/com/kizitonwose/calendarview/ui/CalendarLayoutManager.kt b/library/src/main/java/com/kizitonwose/calendarview/ui/CalendarLayoutManager.kt
index 011fe95c..cf84d367 100644
--- a/library/src/main/java/com/kizitonwose/calendarview/ui/CalendarLayoutManager.kt
+++ b/library/src/main/java/com/kizitonwose/calendarview/ui/CalendarLayoutManager.kt
@@ -11,7 +11,7 @@ import com.kizitonwose.calendarview.CalendarView
 import com.kizitonwose.calendarview.model.CalendarDay
 import com.kizitonwose.calendarview.model.ScrollMode
 import com.kizitonwose.calendarview.utils.NO_INDEX
-import org.threeten.bp.YearMonth
+import java.time.YearMonth
 
 internal class CalendarLayoutManager(private val calView: CalendarView, @RecyclerView.Orientation orientation: Int) :
     LinearLayoutManager(calView.context, orientation, false) {
@@ -23,7 +23,7 @@ internal class CalendarLayoutManager(private val calView: CalendarView, @Recycle
         get() = calView.context
 
     fun scrollToMonth(month: YearMonth) {
-        scrollToPosition(adapter.getAdapterPosition(month))
+        scrollToPositionWithOffset(adapter.getAdapterPosition(month), 0)
         calView.post { adapter.notifyMonthScrollListenerIfNeeded() }
     }
 
@@ -45,7 +45,7 @@ internal class CalendarLayoutManager(private val calView: CalendarView, @Recycle
 
     fun scrollToDay(day: CalendarDay) {
         val monthPosition = adapter.getAdapterPosition(day)
-        scrollToPosition(monthPosition)
+        scrollToPositionWithOffset(monthPosition, 0)
         // Can't target a specific day in a paged calendar.
         if (calView.scrollMode == ScrollMode.PAGED) return
         calView.post {
diff --git a/library/src/main/java/com/kizitonwose/calendarview/utils/Extensions.kt b/library/src/main/java/com/kizitonwose/calendarview/utils/Extensions.kt
index 472033fe..888ae586 100644
--- a/library/src/main/java/com/kizitonwose/calendarview/utils/Extensions.kt
+++ b/library/src/main/java/com/kizitonwose/calendarview/utils/Extensions.kt
@@ -5,8 +5,8 @@ import android.view.LayoutInflater
 import android.view.View
 import android.view.ViewGroup
 import androidx.annotation.LayoutRes
-import org.threeten.bp.LocalDate
-import org.threeten.bp.YearMonth
+import java.time.LocalDate
+import java.time.YearMonth
 
 internal fun ViewGroup.inflate(@LayoutRes layoutRes: Int, attachToRoot: Boolean = false): View {
     return LayoutInflater.from(context).inflate(layoutRes, this, attachToRoot)
diff --git a/library/src/test/java/com/kizitonwose/calenderview/CalenderViewTests.kt b/library/src/test/java/com/kizitonwose/calenderview/CalenderViewTests.kt
index 18abbb5f..f3139e72 100644
--- a/library/src/test/java/com/kizitonwose/calenderview/CalenderViewTests.kt
+++ b/library/src/test/java/com/kizitonwose/calenderview/CalenderViewTests.kt
@@ -6,8 +6,8 @@ import com.kizitonwose.calendarview.model.MonthConfig
 import com.kizitonwose.calendarview.model.OutDateStyle
 import org.junit.Assert.assertTrue
 import org.junit.Test
-import org.threeten.bp.DayOfWeek
-import org.threeten.bp.YearMonth
+import java.time.DayOfWeek
+import java.time.YearMonth
 
 /**
  * These are core functionality tests.
diff --git a/sample/build.gradle b/sample/build.gradle
index 3bef53f9..e0d894eb 100644
--- a/sample/build.gradle
+++ b/sample/build.gradle
@@ -21,6 +21,7 @@ android {
         }
     }
     compileOptions {
+        coreLibraryDesugaringEnabled true
         sourceCompatibility = 1.8
         targetCompatibility = 1.8
     }
@@ -32,6 +33,7 @@ android {
 dependencies {
     implementation fileTree(dir: 'libs', include: ['*.jar'])
     implementation project(':library')
+    coreLibraryDesugaring "com.android.tools:desugar_jdk_libs:$versions.desugar_jdk_libs"
     implementation "org.jetbrains.kotlin:kotlin-stdlib-jdk8:$versions.kotlin_lang"
     implementation "androidx.legacy:legacy-support-v4:$versions.androidx_legacy"
     implementation "androidx.appcompat:appcompat:$versions.androidx_appcompat"
diff --git a/sample/src/androidTest/java/com/kizitonwose/calenderviewsample/CalenderViewTests.kt b/sample/src/androidTest/java/com/kizitonwose/calenderviewsample/CalenderViewTests.kt
index 30cc5535..799fba86 100644
--- a/sample/src/androidTest/java/com/kizitonwose/calenderviewsample/CalenderViewTests.kt
+++ b/sample/src/androidTest/java/com/kizitonwose/calenderviewsample/CalenderViewTests.kt
@@ -27,9 +27,9 @@ import org.junit.Before
 import org.junit.Rule
 import org.junit.Test
 import org.junit.runner.RunWith
-import org.threeten.bp.LocalDate
-import org.threeten.bp.YearMonth
 import java.lang.Thread.sleep
+import java.time.LocalDate
+import java.time.YearMonth
 
 /**
  * These are UI behaviour tests.
diff --git a/sample/src/main/java/com/kizitonwose/calendarviewsample/CalendarViewApp.kt b/sample/src/main/java/com/kizitonwose/calendarviewsample/CalendarViewApp.kt
index 3a0f66dc..5a75c4b8 100644
--- a/sample/src/main/java/com/kizitonwose/calendarviewsample/CalendarViewApp.kt
+++ b/sample/src/main/java/com/kizitonwose/calendarviewsample/CalendarViewApp.kt
@@ -1,13 +1,10 @@
 package com.kizitonwose.calendarviewsample
 
 import android.app.Application
-import com.jakewharton.threetenabp.AndroidThreeTen
 
 class CalendarViewApp : Application() {
 
     override fun onCreate() {
         super.onCreate()
-        // Initialize ThreeTenABP library
-        AndroidThreeTen.init(this)
     }
 }
diff --git a/sample/src/main/java/com/kizitonwose/calendarviewsample/Example1Fragment.kt b/sample/src/main/java/com/kizitonwose/calendarviewsample/Example1Fragment.kt
index 62d7fb3f..e48eb040 100644
--- a/sample/src/main/java/com/kizitonwose/calendarviewsample/Example1Fragment.kt
+++ b/sample/src/main/java/com/kizitonwose/calendarviewsample/Example1Fragment.kt
@@ -18,10 +18,10 @@ import com.kizitonwose.calendarview.utils.next
 import com.kizitonwose.calendarview.utils.yearMonth
 import com.kizitonwose.calendarviewsample.databinding.Example1CalendarDayBinding
 import com.kizitonwose.calendarviewsample.databinding.Example1FragmentBinding
-import org.threeten.bp.LocalDate
-import org.threeten.bp.YearMonth
-import org.threeten.bp.format.DateTimeFormatter
-import org.threeten.bp.format.TextStyle
+import java.time.LocalDate
+import java.time.YearMonth
+import java.time.format.DateTimeFormatter
+import java.time.format.TextStyle
 import java.util.*
 
 class Example1Fragment : BaseFragment(R.layout.example_1_fragment), HasToolbar {
diff --git a/sample/src/main/java/com/kizitonwose/calendarviewsample/Example2Fragment.kt b/sample/src/main/java/com/kizitonwose/calendarviewsample/Example2Fragment.kt
index 60a051ae..a9d910be 100644
--- a/sample/src/main/java/com/kizitonwose/calendarviewsample/Example2Fragment.kt
+++ b/sample/src/main/java/com/kizitonwose/calendarviewsample/Example2Fragment.kt
@@ -19,9 +19,9 @@ import com.kizitonwose.calendarview.ui.ViewContainer
 import com.kizitonwose.calendarviewsample.databinding.Example2CalendarDayBinding
 import com.kizitonwose.calendarviewsample.databinding.Example2CalendarHeaderBinding
 import com.kizitonwose.calendarviewsample.databinding.Example2FragmentBinding
-import org.threeten.bp.LocalDate
-import org.threeten.bp.YearMonth
-import org.threeten.bp.format.DateTimeFormatter
+import java.time.LocalDate
+import java.time.YearMonth
+import java.time.format.DateTimeFormatter
 
 class Example2Fragment : BaseFragment(R.layout.example_2_fragment), HasToolbar, HasBackButton {
 
diff --git a/sample/src/main/java/com/kizitonwose/calendarviewsample/Example3Fragment.kt b/sample/src/main/java/com/kizitonwose/calendarviewsample/Example3Fragment.kt
index e06eab42..62377bb0 100644
--- a/sample/src/main/java/com/kizitonwose/calendarviewsample/Example3Fragment.kt
+++ b/sample/src/main/java/com/kizitonwose/calendarviewsample/Example3Fragment.kt
@@ -26,9 +26,9 @@ import com.kizitonwose.calendarviewsample.databinding.Example3CalendarDayBinding
 import com.kizitonwose.calendarviewsample.databinding.Example3CalendarHeaderBinding
 import com.kizitonwose.calendarviewsample.databinding.Example3EventItemViewBinding
 import com.kizitonwose.calendarviewsample.databinding.Example3FragmentBinding
-import org.threeten.bp.LocalDate
-import org.threeten.bp.YearMonth
-import org.threeten.bp.format.DateTimeFormatter
+import java.time.LocalDate
+import java.time.YearMonth
+import java.time.format.DateTimeFormatter
 import java.util.*
 
 data class Event(val id: String, val text: String, val date: LocalDate)
diff --git a/sample/src/main/java/com/kizitonwose/calendarviewsample/Example4Fragment.kt b/sample/src/main/java/com/kizitonwose/calendarviewsample/Example4Fragment.kt
index 22f22638..80f80cf0 100644
--- a/sample/src/main/java/com/kizitonwose/calendarviewsample/Example4Fragment.kt
+++ b/sample/src/main/java/com/kizitonwose/calendarviewsample/Example4Fragment.kt
@@ -23,10 +23,10 @@ import com.kizitonwose.calendarview.ui.ViewContainer
 import com.kizitonwose.calendarviewsample.databinding.Example4CalendarDayBinding
 import com.kizitonwose.calendarviewsample.databinding.Example4CalendarHeaderBinding
 import com.kizitonwose.calendarviewsample.databinding.Example4FragmentBinding
-import org.threeten.bp.LocalDate
-import org.threeten.bp.YearMonth
-import org.threeten.bp.format.DateTimeFormatter
-import org.threeten.bp.format.TextStyle
+import java.time.LocalDate
+import java.time.YearMonth
+import java.time.format.DateTimeFormatter
+import java.time.format.TextStyle
 import java.util.*
 
 class Example4Fragment : BaseFragment(R.layout.example_4_fragment), HasToolbar, HasBackButton {
diff --git a/sample/src/main/java/com/kizitonwose/calendarviewsample/Example5Fragment.kt b/sample/src/main/java/com/kizitonwose/calendarviewsample/Example5Fragment.kt
index 31cb17b6..00a40105 100644
--- a/sample/src/main/java/com/kizitonwose/calendarviewsample/Example5Fragment.kt
+++ b/sample/src/main/java/com/kizitonwose/calendarviewsample/Example5Fragment.kt
@@ -23,11 +23,11 @@ import com.kizitonwose.calendarviewsample.databinding.Example5CalendarDayBinding
 import com.kizitonwose.calendarviewsample.databinding.Example5CalendarHeaderBinding
 import com.kizitonwose.calendarviewsample.databinding.Example5EventItemViewBinding
 import com.kizitonwose.calendarviewsample.databinding.Example5FragmentBinding
-import org.threeten.bp.LocalDate
-import org.threeten.bp.LocalDateTime
-import org.threeten.bp.YearMonth
-import org.threeten.bp.format.DateTimeFormatter
-import org.threeten.bp.format.TextStyle
+import java.time.LocalDate
+import java.time.LocalDateTime
+import java.time.YearMonth
+import java.time.format.DateTimeFormatter
+import java.time.format.TextStyle
 import java.util.*
 
 data class Flight(val time: LocalDateTime, val departure: Airport, val destination: Airport, @ColorRes val color: Int) {
diff --git a/sample/src/main/java/com/kizitonwose/calendarviewsample/Example6Fragment.kt b/sample/src/main/java/com/kizitonwose/calendarviewsample/Example6Fragment.kt
index 88a96624..b17e11c4 100644
--- a/sample/src/main/java/com/kizitonwose/calendarviewsample/Example6Fragment.kt
+++ b/sample/src/main/java/com/kizitonwose/calendarviewsample/Example6Fragment.kt
@@ -18,8 +18,8 @@ import com.kizitonwose.calendarview.ui.ViewContainer
 import com.kizitonwose.calendarviewsample.databinding.Example6CalendarDayBinding
 import com.kizitonwose.calendarviewsample.databinding.Example6CalendarHeaderBinding
 import com.kizitonwose.calendarviewsample.databinding.Example6FragmentBinding
-import org.threeten.bp.YearMonth
-import org.threeten.bp.format.DateTimeFormatter
+import java.time.YearMonth
+import java.time.format.DateTimeFormatter
 
 // We assign this class to the `monthViewClass` attribute in XML.
 // See usage in example_6_fragment.xml
diff --git a/sample/src/main/java/com/kizitonwose/calendarviewsample/Example7Fragment.kt b/sample/src/main/java/com/kizitonwose/calendarviewsample/Example7Fragment.kt
index 1cf19861..3630277e 100644
--- a/sample/src/main/java/com/kizitonwose/calendarviewsample/Example7Fragment.kt
+++ b/sample/src/main/java/com/kizitonwose/calendarviewsample/Example7Fragment.kt
@@ -12,10 +12,10 @@ import com.kizitonwose.calendarview.ui.DayBinder
 import com.kizitonwose.calendarview.ui.ViewContainer
 import com.kizitonwose.calendarviewsample.databinding.Example7CalendarDayBinding
 import com.kizitonwose.calendarviewsample.databinding.Example7FragmentBinding
-import org.threeten.bp.DayOfWeek
-import org.threeten.bp.LocalDate
-import org.threeten.bp.YearMonth
-import org.threeten.bp.format.DateTimeFormatter
+import java.time.DayOfWeek
+import java.time.LocalDate
+import java.time.YearMonth
+import java.time.format.DateTimeFormatter
 
 class Example7Fragment : BaseFragment(R.layout.example_7_fragment), HasToolbar, HasBackButton {
 
diff --git a/sample/src/main/java/com/kizitonwose/calendarviewsample/Extensions.kt b/sample/src/main/java/com/kizitonwose/calendarviewsample/Extensions.kt
index 9a25d92f..b79cb769 100644
--- a/sample/src/main/java/com/kizitonwose/calendarviewsample/Extensions.kt
+++ b/sample/src/main/java/com/kizitonwose/calendarviewsample/Extensions.kt
@@ -12,8 +12,8 @@ import androidx.annotation.ColorRes
 import androidx.annotation.DrawableRes
 import androidx.annotation.LayoutRes
 import androidx.core.content.ContextCompat
-import org.threeten.bp.DayOfWeek
-import org.threeten.bp.temporal.WeekFields
+import java.time.DayOfWeek
+import java.time.temporal.WeekFields
 import java.util.*
 
 fun View.makeVisible() {
diff --git a/sample/src/main/java/com/kizitonwose/calendarviewsample/Utils.kt b/sample/src/main/java/com/kizitonwose/calendarviewsample/Utils.kt
index 3bd39f84..20991566 100644
--- a/sample/src/main/java/com/kizitonwose/calendarviewsample/Utils.kt
+++ b/sample/src/main/java/com/kizitonwose/calendarviewsample/Utils.kt
@@ -1,6 +1,6 @@
 package com.kizitonwose.calendarviewsample
 
-import org.threeten.bp.YearMonth
+import java.time.YearMonth
 
 private typealias Airport = Flight.Airport