diff --git a/app/build.gradle b/app/build.gradle
index b741af4a9..62e8fb689 100644
--- a/app/build.gradle
+++ b/app/build.gradle
@@ -249,6 +249,10 @@ dependencies {
     implementation 'com.google.protobuf:protobuf-javalite:3.10.0'
     implementation 'com.android.volley:volley:1.2.1'
 
+    // JSR-310 timezones backport for Android, since we're still API 21
+    implementation 'com.jakewharton.threetenabp:threetenabp:1.4.0'
+    testImplementation 'org.threeten:threetenbp:1.6.0'
+
     // Android SDK bundles org.json, but we need an actual implementation to replace the stubs in tests
     testImplementation 'org.json:json:20180813'
 }
diff --git a/app/src/main/java/nodomain/freeyourgadget/gadgetbridge/GBApplication.java b/app/src/main/java/nodomain/freeyourgadget/gadgetbridge/GBApplication.java
index 06f171332..93f8c40a4 100644
--- a/app/src/main/java/nodomain/freeyourgadget/gadgetbridge/GBApplication.java
+++ b/app/src/main/java/nodomain/freeyourgadget/gadgetbridge/GBApplication.java
@@ -99,6 +99,8 @@ import static nodomain.freeyourgadget.gadgetbridge.model.DeviceType.fromKey;
 import static nodomain.freeyourgadget.gadgetbridge.util.GB.NOTIFICATION_CHANNEL_HIGH_PRIORITY_ID;
 import static nodomain.freeyourgadget.gadgetbridge.util.GB.NOTIFICATION_ID_ERROR;
 
+import com.jakewharton.threetenabp.AndroidThreeTen;
+
 /**
  * Main Application class that initializes and provides access to certain things like
  * logging and DB access.
@@ -184,6 +186,9 @@ public class GBApplication extends Application {
             return;
         }
 
+        // Initialize the timezones library
+        AndroidThreeTen.init(this);
+
         sharedPrefs = PreferenceManager.getDefaultSharedPreferences(context);
         prefs = new Prefs(sharedPrefs);
         gbPrefs = new GBPrefs(prefs);
diff --git a/app/src/main/java/nodomain/freeyourgadget/gadgetbridge/service/devices/huami/Huami2021Weather.java b/app/src/main/java/nodomain/freeyourgadget/gadgetbridge/service/devices/huami/Huami2021Weather.java
index 15f595a85..d3c02f617 100644
--- a/app/src/main/java/nodomain/freeyourgadget/gadgetbridge/service/devices/huami/Huami2021Weather.java
+++ b/app/src/main/java/nodomain/freeyourgadget/gadgetbridge/service/devices/huami/Huami2021Weather.java
@@ -26,6 +26,8 @@ import net.e175.klaus.solarpositioning.SPA;
 
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
+import org.threeten.bp.LocalDate;
+import org.threeten.bp.format.DateTimeFormatter;
 
 import java.text.SimpleDateFormat;
 import java.util.ArrayList;
diff --git a/app/src/main/java/nodomain/freeyourgadget/gadgetbridge/service/devices/huami/HuamiSupport.java b/app/src/main/java/nodomain/freeyourgadget/gadgetbridge/service/devices/huami/HuamiSupport.java
index 33cc3d053..42e65a75d 100644
--- a/app/src/main/java/nodomain/freeyourgadget/gadgetbridge/service/devices/huami/HuamiSupport.java
+++ b/app/src/main/java/nodomain/freeyourgadget/gadgetbridge/service/devices/huami/HuamiSupport.java
@@ -39,17 +39,16 @@ import net.e175.klaus.solarpositioning.SPA;
 import org.apache.commons.lang3.ArrayUtils;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
-
+import org.threeten.bp.Instant;
+import org.threeten.bp.ZoneId;
+import org.threeten.bp.zone.ZoneOffsetTransition;
+import org.threeten.bp.zone.ZoneRules;
 
 import java.io.ByteArrayOutputStream;
 import java.io.IOException;
 import java.nio.ByteBuffer;
 import java.nio.ByteOrder;
 import java.nio.charset.StandardCharsets;
-import java.time.Instant;
-import java.time.ZoneId;
-import java.time.zone.ZoneOffsetTransition;
-import java.time.zone.ZoneRules;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Calendar;