Unix Timestamp Converter

Convert Unix timestamps in seconds, milliseconds, microseconds or nanoseconds to dates, and dates back to timestamps.

Current Unix time

Timestamp or date

Read a number as

Converts a Unix timestamp to a date — in UTC, in your time zone and in any other — and a date back to timestamps in seconds, milliseconds, microseconds and nanoseconds. It reads the unit from the number's length, keeps nanoseconds exact, and converts a pasted list at once.

How timestamps are read

A Unix timestamp counts seconds since 00:00:00 UTC on 1 January 1970, the Unix epoch; earlier instants are negative. POSIX defines it without leap seconds: every day is exactly 86,400 seconds, so a timestamp maps to a date by arithmetic alone. Timestamps are the same everywhere; only the date and time shown for one depends on the time zone.

Systems store timestamps in different units, and the digits give them away. Auto reads up to 11 digits as seconds, 12 to 14 as milliseconds, 15 to 17 as microseconds and 18 or more as nanoseconds, counting the digits without a minus sign; the result says which it chose, and the unit can be set by hand. A decimal fraction is kept, to the nanosecond.

Dates are read only in RFC 3339 form — a date, a time and an offset, such as 2025-01-01T05:30:00+05:30 or 2025-01-01T00:00:00Z. Browsers disagree on what other forms mean, so they are rejected rather than guessed. Instants must lie within 8.64 × 10¹⁵ milliseconds of the epoch, the range JavaScript dates cover (years −271,821 to 275,760).

Examples

A timestamp in seconds

Input: 1735689600
Read as: seconds
UTC: 2025-01-01T00:00:00Z
India: 2025-01-01T05:30:00+05:30
New York: 2024-12-31T19:00:00-05:00

The same instant is midnight in London and already morning in India, while New York is still on the evening before.

Milliseconds from JavaScript

Input: 1735689600123
Read as: milliseconds
UTC: 2025-01-01T00:00:00.123Z

Date.now() gives milliseconds, 13 digits for any date between 2001 and 2286.

Before 1970

Input: -1
UTC: 1969-12-31T23:59:59Z

One second before the epoch.

Notable timestamps

Timestamps in seconds and the instants they name

Timestamp	UTC	Note
0	1970-01-01T00:00:00Z	The epoch
1000000000	2001-09-09T01:46:40Z	The first 10-digit timestamp
1234567890	2009-02-13T23:31:30Z	The digits 1 to 0 in order
2000000000	2033-05-18T03:33:20Z	Two billion seconds
2147483647	2038-01-19T03:14:07Z	The largest signed 32-bit value: where 32-bit clocks overflow
4294967295	2106-02-07T06:28:15Z	The largest unsigned 32-bit value

Frequently asked questions

JavaScript: Math.floor(Date.now() / 1000)
Python: import time; int(time.time())
PostgreSQL: SELECT EXTRACT(EPOCH FROM now())::bigint;
MySQL: SELECT UNIX_TIMESTAMP();
Shell (Linux, macOS): date +%s

A timestamp in seconds read as milliseconds lands a few weeks after the epoch: 1735689600 as milliseconds is 1970-01-21T02:08:09.6Z. The other way round, a millisecond value read as seconds lands tens of thousands of years ahead. Auto picks the unit by the number of digits, so check the unit the result names.