diff --git a/apps/calendar/ChangeLog b/apps/calendar/ChangeLog
index d737ec6d4..b5a5fbe2f 100644
--- a/apps/calendar/ChangeLog
+++ b/apps/calendar/ChangeLog
@@ -20,3 +20,4 @@
 0.17: Load holidays before events so the latter is not overpainted
 0.18: Minor code improvements
 0.19: Read events synchronized from Gadgetbridge
+0.20: Correct start time of all-day events synchronized from Gadgetbridge
diff --git a/apps/calendar/calendar.js b/apps/calendar/calendar.js
index ea06b70e8..d6eefce39 100644
--- a/apps/calendar/calendar.js
+++ b/apps/calendar/calendar.js
@@ -62,9 +62,11 @@ const loadEvents = () => {
   }));
   // all events synchronized from Gadgetbridge
   events = events.concat((require("Storage").readJSON("android.calendar.json",1) || []).map(a => {
-    // timestamp is in seconds, Date requires milliseconds
-    const date = new Date(a.timestamp * 1000);
-    return {date: date, msg: a.title, type: "e"};
+    // All-day events always start at 00:00:00 UTC, so we need to "undo" the
+    // timezone offsetting to make sure that the day is correct.
+    const offset = a.allDay ? new Date().getTimezoneOffset() * 60 : 0
+    const date = new Date((a.timestamp+offset) * 1000);
+    return {date: date, msg: a.title, type: a.allDay ? "o" : "e"};
   }));
 };
 
diff --git a/apps/calendar/metadata.json b/apps/calendar/metadata.json
index 5f5f21b27..36713a487 100644
--- a/apps/calendar/metadata.json
+++ b/apps/calendar/metadata.json
@@ -1,7 +1,7 @@
 {
   "id": "calendar",
   "name": "Calendar",
-  "version": "0.19",
+  "version": "0.20",
   "description": "Monthly calendar, displays holidays uploaded from the web interface and scheduled events.",
   "icon": "calendar.png",
   "screenshots": [{"url":"screenshot_calendar.png"}],