Timestamp Add/Subtract Calculator

Shift an epoch value by an integer duration locally and inspect the resulting timestamp and UTC date.

Timestamp

Timestamp unit

Signed amount

Duration unit

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Unix/POSIX time is based on seconds since the 1970-01-01 UTC epoch. Browser date rendering uses JavaScript Date/Intl; sub-millisecond epoch arithmetic is preserved with BigInt where the tool exposes it.

How to use this Timestamp Add/Subtract Calculator

Add or subtract days, hours, minutes, seconds, or milliseconds from a Unix timestamp. Enter your values above and the result is calculated directly in your browser. No account is required.

Fast answer, clear inputs

This tool is built around one job: give the answer quickly without forcing a signup or hiding the result. Related tools are linked nearby when the next calculation or conversion is useful.