What Does OneCal Sync?

OneCal keeps a limited window of events in sync at a time to ensure reliable performance. This page explains which events are synced, and which ones are intentionally left out.

How far into the future does OneCal sync?

OneCal syncs events up to 1 year ahead for Google and iCloud calendars, and up to 3 months ahead for Outlook calendars.

Events scheduled beyond these ranges may not sync consistently. The time window updates automatically as time progresses, so events sync as they come within range, without you having to do anything. These windows exist to maintain reliability, as there is a limit to how many events OneCal can keep in sync without running into issues with the underlying calendar provider.

Does OneCal sync past events?

No. If your past events are not syncing to another calendar, this is expected behavior. OneCal is mainly intended for keeping your current and future availability in sync across calendars, and is not intended for syncing historical events. Since the number of events OneCal can keep in sync is limited, we prioritize current and future events.

Recurring events that extend into the future also sync in the past, but individual events that only exist in the past are not synced.

Are changes to clone events synced back to the original?

No. Changes you make to a clone event are never propagated back to the original event. This aligns with one of our core principles: never modifying your original events.

Clone events can be safely modified, since any change to them is reversible: clones can be removed from your calendars and re-created without consequences, even if something goes wrong. Changes to your original meetings, however, can have lasting impacts if other guests are involved. For this reason, we currently have no plans to sync changes from clones back to the originals.