The sync-wide settings: a sync's name, how much history it copies on its first run, and how far ahead it reaches.
The third section in a sync's settings, headed 03 · Sync-wide. Three settings that describe the sync as a whole rather than any individual copy.
Fills in automatically from the calendars you picked. You can change it to anything; it's only ever shown to you.
It can't be blank. If you clear it, the button to start or save the sync stays greyed out and a red line appears under the settings.
None, Past week, or Past month. None is the default, so a new sync starts from today and leaves your history alone.
This only runs the first time the sync starts. Choosing None and changing your mind later doesn't reach back and fetch anything — the setting isn't offered again once a sync exists. There's also no way to go further back than a month, and no full-history backfill to request.
If you need years of history in another calendar, export and import it directly rather than syncing it.
30 days on Free, 1 year on Plus, unlimited on Pro. Events starting beyond that window aren't copied yet.
Nothing is lost. The event isn't deleted, just not copied yet. Don't count on it copying itself in as time passes, though: whether that happens depends on your calendar provider, and on some it doesn't. If something's missing, open the sync's menu and choose Re-sync — that's the reliable way to bring in anything that's now inside your window.
This is the usual reason a healthy sync looks incomplete. March copied, July didn't, and it reads as broken. Find an event that didn't copy, check its start date, count the days.
A per-sync window can only be narrower than your plan allows, never wider. Pick 30 days on Pro and you get 30 days.
Repeating events ignore this entirely. A weekly standup transfers as one repeating event with its repeat rule attached, including occurrences years out, so the window has nothing to apply to. A Free plan with a 30-day window can still show a repeating event five years ahead.
Change the setting on the sync. An upgrade widens what you're allowed to pick but doesn't move an existing sync's window for you. Set the wider option, then open the sync's menu and choose Re-sync.
The catch-up isn't instant. A year of events is a lot to write, and calendar providers limit how fast anyone can write to them. Give it a few runs.
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