Recurrence anchor

Every repeating task has to answer one question when you tick it off: what is the next date? There are only two sensible answers, and they disagree the moment you are late.

Say a task repeats every two weeks and was due on the 1st. You finish it on the 5th. Anchored to the schedule, the next one is the 15th — the rhythm holds, and being late does not move it. Anchored to completion, the next one is the 19th — two weeks from when the thing was actually done.

Both are correct, for different tasks. Rent is a schedule; it does not care when you paid last month. Plants are a completion; they care about the last time they were watered and nothing else. An app that offers only one of the two forces you to fake the other, which is where the frustration in this whole topic comes from.

There is no shared vocabulary here, and that is part of why the feature is served so badly. Nobody searches for “recurrence anchor”; they search for the failure.

• Todoist expresses it as punctuation inside the typed date string: every 3 months counts from the original date, every! 3 months counts from the day you completed it. It is a real capability and it is genuinely powerful — but it is a parsed string rather than a structured rule, so what you get is not always what you meant, and editing it later means editing the string.
• TaskPocket makes it two labelled options in the repeat editor, “on a schedule” and “after completion”, and shows the rule back to you as a sentence before you save it.

The anchor is one of two things people confuse when a repeat behaves unexpectedly. The other is which date field the repeat attaches to — see start dates and deadlines, because a repeat anchored to a start date and a repeat anchored to a deadline are different tasks. If you have arrived here from a competitor's repeat editor, the answers section covers what the other apps do and do not do.