How to use the Unix Timestamp Converter with Time Zones and Batch Mode
- Paste a value. Use a Unix timestamp in seconds or milliseconds, an ISO 8601 string, an RFC 2822 date or text like Nov 1, 2026 1:30 PM. The unit is detected from the number of digits.
- Choose the time zone. Pick any IANA zone such as Europe/Madrid or America/New_York. Text without an offset is read in that zone.
- Read every format. See Unix seconds and milliseconds, ISO with offset, UTC with Z, RFC 2822, week number, day of year and relative time such as in 3 hours.
- Copy the scheduler format. Copy ISO with offset or UTC Z, the unambiguous forms that scheduling APIs and MCP clients accept. Paste many lines in batch mode to convert a whole list.
How timestamps are converted
What the converter does
A Unix timestamp is a count of seconds since 1970-01-01T00:00:00Z, not counting leap seconds. All conversion runs in your browser. Time zone offsets and daylight saving rules come from your browser's built-in Intl support for the IANA time zone database, so zone data follows your browser version rather than a copy bundled here.
Local text is turned into an instant by finding the zone offset on either side of the guess and keeping the offset that agrees with itself. That gives one answer for normal times, two for the repeated hour (the earlier is used) and none for the skipped hour (moved forward by the gap).
Rules and sources
ISO 8601 date and time with offset or Z is read as written. RFC 2822 dates, such as Tue, 03 Nov 2026 14:30:00 +0100, are read with their numeric offset or common names like GMT and EST. Week numbers follow the ISO 8601 rule: weeks start on Monday and week 1 holds the first Thursday, so 1 January 2027 is in week 53 of 2026. The 32-bit limits are 2147483647 for signed and 4294967295 for unsigned.
For scheduling, TimeToPost's MCP scheduler documents scheduledAt as a future ISO datetime, as checked in its tool description in October 2026.
Limitations
Digit counting cannot tell milliseconds before March 1973 from seconds, because both have 11 digits or fewer. Force the unit when you work with old data. Leap seconds are not modelled, as Unix time ignores them. Batch mode converts the first 500 non-empty lines.
Frequently asked questions
Is a Unix timestamp in seconds or milliseconds?
It depends on the system. The classic Unix timestamp counts seconds since 1 January 1970 UTC and has 10 digits today, like 1700000000. JavaScript, Java and many web APIs use milliseconds with 13 digits, like 1700000000000. This converter reads up to 11 digits as seconds, 12 to 14 as milliseconds, 15 to 17 as microseconds and longer values as nanoseconds, and lets you force a unit.
What is the Year 2038 problem?
A signed 32-bit integer holds at most 2147483647 seconds, which is 03:14:07 UTC on 19 January 2038. One second later the counter wraps to a negative number and software that stored time that way reads December 1901. Systems with 64-bit time are unaffected. The converter flags any value that does not fit in 32 bits.
Why does the same local time map to two timestamps in autumn?
When clocks go back, one hour is repeated. In Europe/Madrid on 25 October 2026, 02:30 happens at 00:30 UTC and again at 01:30 UTC. The converter uses the first occurrence and marks the result as ambiguous so you can add an explicit offset like +01:00 when you mean the second.
What happens with a time that does not exist in spring?
When clocks go forward an hour is skipped. In Europe/Madrid on 29 March 2026, 02:30 never happens. The converter moves it forward by the length of the gap to 03:30 local time and flags it, the same way the JavaScript Temporal proposal resolves it by default.
What time format should I send to a scheduling API?
Send ISO 8601 with an explicit offset, like 2026-10-25T09:30:00+01:00, or in UTC with a Z, like 2026-10-25T08:30:00Z. Both name one exact instant. TimeToPost's MCP scheduling tool takes a future ISO datetime for scheduledAt, so either form works, and a bare local time without an offset leaves the zone up to the receiver.
Can it convert negative timestamps and dates before 1970?
Yes. A negative number counts back from the epoch, so -1 is 23:59:59 UTC on 31 December 1969 and -86400 is the start of that day. Dates up to about 270,000 years either side of 1970 are inside the JavaScript date range this page relies on.