Convert Unix seconds or milliseconds to dates and back, with ISO output and a chosen time zone. The Unix epoch starts at 1970-01-01 00:00:00 UTC; a time zone changes the display, not the timestamp of the same instant.
Automatic recognition considers 1–10 digits as seconds and 13 digits as milliseconds; please select other lengths manually. The date can be written as 2026-09-08 09:00:00; without offset, the selected time zone is used. local is the browser time zone.
10 / 100 characters
Shortcut key: Ctrl/⌘+Enter. Modifying inputs or options clears old results.
The same time in Asia/Shanghai is 2023-11-15 06:13:20; the timestamp itself does not change.
Automatic mode recognizes digits 1–10 as seconds and digits 13 as milliseconds; digits 11–12 must be selected manually to avoid guessing. Seconds support three decimal places.
The daylight saving time switch may cause a moment to not exist or appear twice. In this case, please write a clear offset after the date, such as -04:00; this tool will not silently select one of them.
Convert between Unix time and ISO date in integer milliseconds, using Luxon and browser IANA time zone data. Dates without an offset are interpreted in the specified time zone; daylight saving time ambiguities or non-existent local times are rejected.
Content check:2026-09-08 · About this site and content description