diff --git a/.github/workflows/android.yml b/.github/workflows/android.yml
index eb419b56..8363ca25 100644
--- a/.github/workflows/android.yml
+++ b/.github/workflows/android.yml
@@ -13,11 +13,11 @@ jobs:
         uses: actions/checkout@v3
         with:
           submodules: recursive
-      - name: set up JDK 11
+      - name: set up JDK 17
         uses: actions/setup-java@v3.10.0
         with:
           distribution: 'zulu'
-          java-version: '11'
+          java-version: '17'
       - name: Restore Cache
         uses: actions/cache@v3.2.6
         with:
diff --git a/app/build.gradle b/app/build.gradle
index 805094cc..ceec57bc 100644
--- a/app/build.gradle
+++ b/app/build.gradle
@@ -10,6 +10,8 @@ editorconfig {
 }
 
 android {
+    namespace 'ws.xsoh.etar'
+    testNamespace 'com.android.calendar.tests'
     compileSdk 33
 
     defaultConfig {
@@ -94,15 +96,15 @@ android {
 dependencies {
 
     // Core
-    implementation 'androidx.core:core-ktx:1.8.0'
+    implementation 'androidx.core:core-ktx:1.10.0'
     implementation fileTree(include: ['*.jar', '*.aar'], dir: 'libs')
     implementation 'androidx.preference:preference:1.1.1'
-    implementation 'androidx.appcompat:appcompat:1.4.1'
-    implementation 'androidx.constraintlayout:constraintlayout:2.1.3'
-    implementation 'com.google.android.material:material:1.5.0'
+    implementation 'androidx.appcompat:appcompat:1.6.1'
+    implementation 'androidx.constraintlayout:constraintlayout:2.1.4'
+    implementation 'com.google.android.material:material:1.8.0'
     testImplementation 'junit:junit:4.13.2'
 
-    coreLibraryDesugaring 'com.android.tools:desugar_jdk_libs:1.1.8'
+    coreLibraryDesugaring 'com.android.tools:desugar_jdk_libs:2.0.3'
 
     // Coroutines
     def coroutines_version = "1.6.0"
diff --git a/app/src/main/java/com/android/calendar/settings/GeneralPreferences.kt b/app/src/main/java/com/android/calendar/settings/GeneralPreferences.kt
index c5d9b03d..5f7e9165 100644
--- a/app/src/main/java/com/android/calendar/settings/GeneralPreferences.kt
+++ b/app/src/main/java/com/android/calendar/settings/GeneralPreferences.kt
@@ -231,7 +231,7 @@ class GeneralPreferences : PreferenceFragmentCompat(),
 
     override fun onStart() {
         super.onStart()
-        preferenceScreen.sharedPreferences.registerOnSharedPreferenceChangeListener(this)
+        preferenceScreen.sharedPreferences?.registerOnSharedPreferenceChangeListener(this)
         setPreferenceListeners(this)
     }
 
@@ -258,7 +258,7 @@ class GeneralPreferences : PreferenceFragmentCompat(),
     }
 
     override fun onStop() {
-        preferenceScreen.sharedPreferences.unregisterOnSharedPreferenceChangeListener(this)
+        preferenceScreen.sharedPreferences?.unregisterOnSharedPreferenceChangeListener(this)
         super.onStop()
     }
 
@@ -403,7 +403,7 @@ class GeneralPreferences : PreferenceFragmentCompat(),
         defaultReminderPref.entries = entries
     }
 
-    override fun onPreferenceTreeClick(preference: Preference?): Boolean {
+    override fun onPreferenceTreeClick(preference: Preference): Boolean {
         when (preference!!.key) {
             KEY_COLOR_PREF -> {
                 showColorPickerDialog()
diff --git a/app/src/main/java/com/android/calendar/settings/MainListPreferences.kt b/app/src/main/java/com/android/calendar/settings/MainListPreferences.kt
index 2e8d05dc..eacc79f3 100644
--- a/app/src/main/java/com/android/calendar/settings/MainListPreferences.kt
+++ b/app/src/main/java/com/android/calendar/settings/MainListPreferences.kt
@@ -75,7 +75,7 @@ class MainListPreferences : PreferenceFragmentCompat() {
             val accountCategoryUniqueKey = "account_category_${calendar.accountName}_${calendar.accountType}"
             var accountCategory = screen.findPreference<PreferenceCategory>(accountCategoryUniqueKey)
             if (accountCategory == null) {
-                accountCategory = PreferenceCategory(context).apply {
+                accountCategory = PreferenceCategory(requireContext()).apply {
                     key = accountCategoryUniqueKey
                     title = calendar.accountName
                     icon = ContextCompat.getDrawable(requireContext(), R.drawable.ic_account_circle)
@@ -89,7 +89,7 @@ class MainListPreferences : PreferenceFragmentCompat() {
             val calendarUniqueKey = "calendar_preference_${calendar.id}"
             var calendarPreference = screen.findPreference<Preference>(calendarUniqueKey)
             if (calendarPreference == null) {
-                calendarPreference = Preference(context)
+                calendarPreference = Preference(requireContext())
                 accountCategory.addPreference(calendarPreference)
             }
             calendarPreference.apply {
@@ -152,12 +152,12 @@ class MainListPreferences : PreferenceFragmentCompat() {
     }
 
     private fun addGeneralPreferences(screen: PreferenceScreen) {
-        val generalPreference = Preference(context).apply {
+        val generalPreference = Preference(requireContext()).apply {
             title = getString(R.string.preferences_list_general)
             icon = ContextCompat.getDrawable(requireContext(), R.drawable.ic_settings)
             fragment = GeneralPreferences::class.java.name
         }
-        val addCaldavPreference = Preference(context).apply {
+        val addCaldavPreference = Preference(requireContext()).apply {
             title = getString(R.string.preferences_list_add_remote)
             icon = ContextCompat.getDrawable(requireContext(), R.drawable.ic_add)
         }
@@ -165,7 +165,7 @@ class MainListPreferences : PreferenceFragmentCompat() {
             launchDavX5Login()
             true
         }
-        val addEtesyncPreference = Preference(context).apply {
+        val addEtesyncPreference = Preference(requireContext()).apply {
             title = getString(R.string.preferences_list_add_remote_etesync)
             icon = ContextCompat.getDrawable(requireContext(), R.drawable.ic_add)
         }
@@ -173,7 +173,7 @@ class MainListPreferences : PreferenceFragmentCompat() {
             launchAddEtesync()
             true
         }
-        val addOfflinePreference = Preference(context).apply {
+        val addOfflinePreference = Preference(requireContext()).apply {
             title = getString(R.string.preferences_list_add_offline)
             icon = ContextCompat.getDrawable(requireContext(), R.drawable.ic_add)
         }
diff --git a/app/src/main/java/com/android/calendar/settings/QuickResponsePreferences.kt b/app/src/main/java/com/android/calendar/settings/QuickResponsePreferences.kt
index 312f85c9..6e167d78 100644
--- a/app/src/main/java/com/android/calendar/settings/QuickResponsePreferences.kt
+++ b/app/src/main/java/com/android/calendar/settings/QuickResponsePreferences.kt
@@ -53,7 +53,7 @@ class QuickResponsePreferences : PreferenceFragmentCompat(), Preference.OnPrefer
 
         responsePreferences = arrayOfNulls(responses.size)
         for ((i, response) in responses.withIndex()) {
-            val responsePreference = EditTextPreference(activity).apply {
+            val responsePreference = EditTextPreference(requireActivity()).apply {
                 setDialogTitle(R.string.quick_response_settings_edit_title)
                 title = response
                 text = response
diff --git a/app/src/main/java/com/android/calendar/settings/SettingsActivity.kt b/app/src/main/java/com/android/calendar/settings/SettingsActivity.kt
index 6ec224f1..8f430820 100644
--- a/app/src/main/java/com/android/calendar/settings/SettingsActivity.kt
+++ b/app/src/main/java/com/android/calendar/settings/SettingsActivity.kt
@@ -81,7 +81,7 @@ class SettingsActivity : AppCompatActivity(),
         val args = pref.extras
         val fragment = supportFragmentManager.fragmentFactory.instantiate(
                 classLoader,
-                pref.fragment
+                pref.fragment!!
         ).apply {
             arguments = args
             setTargetFragment(caller, 0)
diff --git a/app/src/main/java/com/android/calendar/settings/ViewDetailsPreferences.kt b/app/src/main/java/com/android/calendar/settings/ViewDetailsPreferences.kt
index aa286823..4b57fec5 100644
--- a/app/src/main/java/com/android/calendar/settings/ViewDetailsPreferences.kt
+++ b/app/src/main/java/com/android/calendar/settings/ViewDetailsPreferences.kt
@@ -77,7 +77,7 @@ class ViewDetailsPreferences : PreferenceFragmentCompat() {
                 val newEntries = Arrays.copyOf(entries, entries.size - 1)
                 displayTime.entries = newEntries
             }
-            if (displayTime.entry == null || displayTime.entry.isEmpty()) {
+            if (displayTime.entry == null || displayTime.entry!!.isEmpty()) {
                 displayTime.value = getDefaultTimeToShow(activity).toString()
             }
         }
@@ -173,7 +173,7 @@ class ViewDetailsPreferences : PreferenceFragmentCompat() {
             return Preferences(context!!)
         }
 
-        fun setDefaultValues(context: Context?) {
+        fun setDefaultValues(context: Context) {
             PreferenceManager.setDefaultValues(context, SHARED_PREFS_NAME, Context.MODE_PRIVATE,
                     R.xml.view_details_preferences, true)
         }
diff --git a/build.gradle b/build.gradle
index 6661e9dd..956b26fd 100644
--- a/build.gradle
+++ b/build.gradle
@@ -1,7 +1,7 @@
 plugins {
-    id 'com.android.application' version '7.2.1' apply false
-    id 'com.android.library' version '7.2.1' apply false
-    id 'org.jetbrains.kotlin.android' version '1.7.0' apply false
+    id 'com.android.application' version '8.0.0' apply false
+    id 'com.android.library' version '8.0.0' apply false
+    id 'org.jetbrains.kotlin.android' version '1.8.0' apply false
     id 'org.ec4j.editorconfig' version "0.0.3" apply false
     id "org.jetbrains.gradle.plugin.idea-ext" version "1.1.5" apply true
 }
diff --git a/external/calendar b/external/calendar
index d47bcc32..04fe66e2 160000
--- a/external/calendar
+++ b/external/calendar
@@ -1 +1 @@
-Subproject commit d47bcc32e0ed9b6378cebcfe531ee9a8fdcc8a21
+Subproject commit 04fe66e252f9c6cf569dfb462004dd99d6e68b00
diff --git a/external/chips b/external/chips
index 397a829e..ad59fc7c 160000
--- a/external/chips
+++ b/external/chips
@@ -1 +1 @@
-Subproject commit 397a829ece6de4f801a7f7fd0d3e7839e5f3fea0
+Subproject commit ad59fc7c1fb3bb6952fb55efdbc31396b7f28248
diff --git a/external/colorpicker b/external/colorpicker
index b9ffe228..c57cf97b 160000
--- a/external/colorpicker
+++ b/external/colorpicker
@@ -1 +1 @@
-Subproject commit b9ffe228e641a23e97d4b23acbb2c9c4fce3efe4
+Subproject commit c57cf97b1a0e0526a80513c56ed74af59bdc1974
diff --git a/external/configuration/common.gradle b/external/configuration/common.gradle
index be83e3e2..3799e5a7 100644
--- a/external/configuration/common.gradle
+++ b/external/configuration/common.gradle
@@ -1,11 +1,16 @@
 apply plugin: 'com.android.library'
 
 android {
-    compileSdk 31
+    compileSdk 33
 
     defaultConfig {
         minSdk 21
-        targetSdk 31
+        targetSdk 33
+    }
+
+    buildFeatures {
+        renderScript true
+        aidl true
     }
 
     sourceSets {
diff --git a/external/timezonepicker b/external/timezonepicker
index bad57781..1fcb55e7 160000
--- a/external/timezonepicker
+++ b/external/timezonepicker
@@ -1 +1 @@
-Subproject commit bad577815fb03f1d4ec1276e6a5250bbbffb9e8e
+Subproject commit 1fcb55e77be051a1cf6c5ba8ac1a95e884a98eb8
diff --git a/gradle.properties b/gradle.properties
index 342a08a0..801fd4ba 100755
--- a/gradle.properties
+++ b/gradle.properties
@@ -23,3 +23,5 @@ kotlin.code.style=official
 # resources declared in the library itself and none from the library's dependencies,
 # thereby reducing the size of the R class for that library
 android.nonTransitiveRClass=false
+android.defaults.buildfeatures.buildconfig=true
+android.nonFinalResIds=false
diff --git a/gradle/wrapper/gradle-wrapper.properties b/gradle/wrapper/gradle-wrapper.properties
index 252a4996..c75b06a9 100644
--- a/gradle/wrapper/gradle-wrapper.properties
+++ b/gradle/wrapper/gradle-wrapper.properties
@@ -1,6 +1,6 @@
 #Tue Nov 16 03:59:46 GMT 2021
 distributionBase=GRADLE_USER_HOME
-distributionUrl=https\://services.gradle.org/distributions/gradle-7.4.1-bin.zip
+distributionUrl=https\://services.gradle.org/distributions/gradle-8.1-bin.zip
 distributionPath=wrapper/dists
 zipStorePath=wrapper/dists
 zipStoreBase=GRADLE_USER_HOME