Why an All-Day Event Moves to a Different Date After Syncing

An all-day event on the wrong date often means one calendar is treating it as a timed appointment, or an import or sync has changed how its dates are stored. Check the original event before moving the copy. Otherwise, the next update may put the wrong date back again.

A birthday, a day of leave, and a midnight-to-midnight appointment can look similar on screen. They are not necessarily stored in the same way, which matters when calendars exchange them across time zones.

Date-only event or midnight appointment?

Open the event in the calendar service that owns it, preferably its web interface. Look for the All day setting. An event that starts at 00:00 and ends at 00:00 the next morning may still be a timed event.

For a birthday reminder, choose an all-day date. For a support shift that starts at midnight in a particular city, a timed appointment may be correct. Base the choice on the commitment: converting a real timed shift to all-day would lose information about its hours.

A timed event can cross a date boundary when viewed elsewhere. Midnight in one country may be the previous afternoon in another. That is a valid conversion, even if the event's title happens to say “Birthday.”

A date range has a beginning and an end

Calendar files distinguish a date from a date-and-time value. They also commonly express an event's ending as the first moment or date outside the event. The iCalendar standard defines this distinction.

A one-day entry for June 12 can have an ending date of June 13 in the file, because the event stops before June 13 begins. It should still occupy only June 12. An import that treats the ending as inclusive can add an extra day.

You do not need to edit the file yourself to diagnose this. Compare the date range shown in the original with the range shown after import or copying. Write down whether the problem adds a day, removes a day, or shifts the entire event.

Find the first place the date changes

Follow one example through the accounts:

Open the original in the source provider's web calendar and record its date range and All day setting.
Open the destination provider's web calendar and inspect the copy.
Compare that destination with the phone or desktop app where you noticed the problem.

If the source and destination web calendars agree but your phone differs, focus on the app's account and display settings. If the destination is already wrong on the web, investigate the import, subscription, or copy process between the accounts.

If you need to trace the update between accounts, keep the same example throughout. Re-importing the file during the investigation can add duplicates and make the original date problem harder to follow.

An all-day copy made by Avum

When Avum is part of the route, inspect the source and destination selected in the Sync Rule Editor. Event timing and all-day status are part of synchronization; fix the source event or rule instead of editing the copy by hand.

Create a small all-day test event in the source, confirm it in the destination, then change its date and inspect the result. If the copy still differs, share that example with Avum support, including the providers and the intended dates. Avoid sending sensitive event details when a generic example reproduces the issue.

Check availability separately, too. A correctly dated all-day event can still be marked Free. See when all-day events block availability if the remaining problem is that people can book the day.

Fixing the original, the feed, or the copy

If you own the original and it should be date-only, correct its all-day setting there. Check one changed event before changing a recurring series or a large calendar.

If the original comes from a school, team, or other published feed, report the specific example to the publisher. Include the original date, the displayed date, and the calendar app involved. Keep a private subscription URL out of public support posts. A temporary personal reminder may help, but label it clearly so it is not confused with the authoritative schedule.

If only the viewing hour or date is unexpected for a timed event, check the difference between floating and fixed times. Moving the appointment to compensate for a display setting changes the underlying commitment.

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