EpochLab

Date Offset Calculator

Move a date by any span, in either direction

One field for the whole offset — `2y 3mo 10d`, `+6 weeks`, `-90 days` — applied in calendar order, with each step shown so you can see what happened.

Questions people ask

The things that come up about date offset calculators, answered plainly.

Does the order of the units matter?

Yes, and it is why the steps are shown. Years and months are applied first, then days — applying them the other way round gives a different answer whenever clamping is involved. This is the order every calendar system uses.

What can I type in the offset field?

Compound spans like `1y 2mo 3d 4h`, plain forms like `90 days` or `-6 weeks`, and ISO 8601 durations like `P1Y2M3D` or `PT90M`.

Related tools

Move a date forwards or backwards by a span, with the calendar's rules applied.

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