Samsung
Sync Calendar Manually auf Samsung
Samsung phones usually refresh the Calendar app only when it starts up. If Calendar keeps running in the background after you close it, One UI treats it as already active and skips the next automatic sync cycle.
Battery saving mode, data saving mode, and per-app background restrictions in Samsung One UI can also pause the sync service entirely. In that case the app shows outdated appointments, calls, and messages until you either restart it or trigger a sync by hand.
To force an update, open Calendar ➔ tap the Menu icon ➔ select Sync now. This pushes any pending changes immediately, without closing the app or rebooting the phone.
If the calendar still does not update after using Sync now, check whether background data is disabled for the app under battery or data settings. Manual sync only refreshes the connection - it cannot restore access if the account itself is blocked from running in the background.
