TIMESTAMP

Date to Timestamp

Pick a date, a time and a time zone to get the Unix timestamp in seconds and milliseconds, plus the ISO 8601 string.

Convert a date and time to a Unix timestamp

Choose a calendar date, a time and a time zone, and the tool returns the matching Unix timestamp in seconds and milliseconds together with the ISO 8601 string. The time zone matters: 12:00 in Tokyo and 12:00 in New York are different moments, so they have different timestamps.

Daylight saving time

Twice a year, clocks in many regions skip an hour or repeat one. A time inside the skipped hour, such as 02:30 on the spring-forward date in New York, never happens, so the tool tells you instead of guessing. A time inside the repeated hour happens twice; the tool uses the first occurrence and says so.

Want the background? Read our comprehensive guide: Time Zones and DST for Developers.

How to use this tool

Choose the date. Use the date picker or type it as YYYY-MM-DD.
Enter the time. Seconds are optional.
Choose the time zone the date and time are written in: local time, UTC or any IANA zone.
Select Convert to timestamp, then copy the seconds, milliseconds or ISO 8601 value.

Examples

The same clock reading gives different timestamps in different zones.

Noon in UTC

2026-09-20 12:30:00 UTC

Unix seconds: 1789907400
Unix milliseconds: 1789907400000
ISO 8601: 2026-09-20T12:30:00.000Z

The same clock time in New York

2026-09-20 12:30:00 America/New_York

Unix seconds: 1789921800
Unix milliseconds: 1789921800000
ISO 8601: 2026-09-20T16:30:00.000Z

The start of the year 2000

2000-01-01 00:00:00 UTC

Unix seconds: 946684800
Unix milliseconds: 946684800000
ISO 8601: 2000-01-01T00:00:00.000Z

Frequently Asked Questions

Which time zone should I choose?

Choose the zone the date and time were written in. UTC is the safest choice for logs and servers. Local time is the right choice for something you noted from your own clock.

How do I get the Unix timestamp of a date in JavaScript?

Use Math.floor(new Date('2026-09-20T12:30:00Z').getTime() / 1000). The trailing Z marks the string as UTC. Without it, JavaScript reads a date-time string in the machine's local time zone.

Does the timestamp change with daylight saving time?

No. A timestamp identifies one instant, so it never changes. Only the local clock reading of that instant changes when daylight saving time starts or ends.

Why is my date rejected?

The date must exist on the calendar (there is no 30 February, and 29 February only exists in leap years) and fall between the years 1 and 9999. A time that falls in a daylight saving gap is also rejected.