Unix timestamp converter
A Unix timestamp counts the seconds since January 1, 1970 at 00:00:00 UTC. 1767225600 is January 1, 2026 at midnight UTC; a 13-digit value is in milliseconds.
- Checked on thousands of cases
- Sources: POSIX.1-2024 (The Open Group)
- Updated November 6, 2026
Date and time (UTC, ISO 8601)
Thursday, January 1, 2026 at 12:00:00 AM · read as Seconds
Your local time
Date → timestamp
Timestamp in seconds
Timestamp in milliseconds
Quick challenge
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Test yourself: every answer is computed by the tool, and the wrong choices are the most common traps.
How it works
Formula: Timestamp = days since 1970-01-01 × 86,400 + seconds since midnight (UTC)
POSIX defines the Epoch as January 1, 1970, 00:00:00 UTC, and counts every day as exactly 86,400 seconds, so leap seconds are left out. The timestamp is the number of whole days since the Epoch × 86,400, plus the seconds since midnight UTC. JavaScript and many APIs count in milliseconds: divide by 1,000 to get seconds. Systems that keep the count in a signed 32-bit integer stop at 2,147,483,647, on January 19, 2038 at 03:14:07 UTC.
Worked examples
Timestamp 0
1970-01-01T00:00:00Z: the Epoch.
Timestamp 1767225600
2026-01-01T00:00:00Z.
The same moment in milliseconds
1767225600000.
Common mistakes
Reading milliseconds as seconds: 1767225600000 s would land in the year 57971.
13 digits for a current date means milliseconds. Divide by 1,000.
Adding the time zone offset to the timestamp.
A timestamp is the same everywhere: only the displayed time changes with the time zone.
Storing dates in signed 32 bits.
The counter stops at 2147483647, on 2038-01-19T03:14:07Z: use 64 bits.
What the calculation leaves out
- As POSIX requires, every day counts exactly 86,400 seconds: leap seconds are not counted.
Notable Unix timestamps
| Moment | Timestamp | Date (UTC) |
|---|---|---|
| The Epoch | 0 | 1970-01-01T00:00:00Z |
| One billion seconds | 1000000000 | 2001-09-09T01:46:40Z |
| The digits 1 to 0 | 1234567890 | 2009-02-13T23:31:30Z |
| Two billion seconds | 2000000000 | 2033-05-18T03:33:20Z |
| Limit of 32-bit counters | 2147483647 | 2038-01-19T03:14:07Z |
Common durations in seconds
| Duration | Seconds |
|---|---|
| 1 minute | 60 |
| 1 hour | 3,600 |
| 1 day | 86,400 |
| 1 week | 604,800 |
| 1 year (365 days) | 31,536,000 |
Frequently asked questions
Is a Unix timestamp in UTC or in local time?
In UTC: the same moment has the same timestamp everywhere in the world. Only the way it is displayed changes with the time zone.
Seconds or milliseconds?
For a current date, a 10-digit value is in seconds (the date +%s command) and a 13-digit value is in milliseconds (Date.now() in JavaScript). The tool tells them apart on its own; you can also choose.
What is the year 2038 problem?
A signed 32-bit counter cannot go past 2,147,483,647 seconds, reached on January 19, 2038 at 03:14:07 UTC. Systems that still store time this way jump back to December 1901; 64-bit counters do not have this limit.