How to use Timestamp Converter
- Select Timestamp → Date or Date → Timestamp.
- Choose seconds or milliseconds. For a date, supply an offset or Z when you need a reproducible instant.
- Run the conversion. Compare the UTC / ISO result as well as the local display.
Worked examples
Use the inputs below to compare the selected mode with a known result. Loading an example replaces the current input.
Convert seconds to UTC
Input
1767225600
Expected result
UTC: 2026-01-01 00:00:00.000 ISO: 2026-01-01T00:00:00.000Z
The local-time line depends on your device. The UTC and ISO values above do not.
Convert an explicit offset
Input
2026-01-01T08:00:00+08:00
Expected result
1767225600
08:00 at UTC+08:00 is the same instant as midnight UTC.
Retain milliseconds
Input
2026-01-01T00:00:00.123Z
Expected result
1767225600123
Selecting seconds instead would return 1767225600 and discard the fractional second.
What this tool does and does not do
Timestamp input must be a safe integer within the JavaScript Date range. Dates accept YYYY-MM-DD, YYYY-MM-DD HH:mm:ss and ISO-style offsets, with up to 3 fractional-second digits. A date without an offset uses the device time zone. Leap-second notation is not supported.
Conversions run in the current browser. Input drafts are temporary; copy or download important results before leaving. See the privacy policy for the separate handling of visits and preferences.
Common questions
Why did I get a date in 1970?
A modern seconds timestamp interpreted as milliseconds is only a few weeks after the epoch. Check the unit supplied by the source; digit count is only a clue.
Why do two devices show different local times?
Local output uses each device’s time zone. Compare the ISO or UTC lines to determine whether the underlying instant matches.
Can I convert an ambiguous daylight-saving time?
A local clock reading can occur twice when clocks move back. Supply an explicit numeric UTC offset to select the intended instant.