Unix Timestamp Converter
Paste a timestamp and the unit is detected; type a date and the timestamp follows. And, what other converters do not do, the NTP timestamp as it travels on the wire. Everything is computed in your browser: nothing is sent.
| Readable date | — |
|---|---|
| Seconds | — |
| Milliseconds | — |
| Microseconds | — |
| Nanoseconds | — |
| ISO 8601 (UTC) | — |
| RFC 3339 (selected zone) | — |
| RFC 2822 (selected zone) | — |
| Relative to now | — |
“Now” takes the time from our server, measured as on Check your machine's time (best round trip out of five), not from your computer, whose clock may have drifted.
The NTP timestamp
NTP does not count from 1970 but from 1 January 1900: an NTP timestamp equals the Unix timestamp plus 2,208,988,800 s. It is 64 bits long: 32 bits of seconds, 32 bits of fraction (a step of about 233 picoseconds). This is the hexadecimal format you read in ntpq (reftime=…) and in the raw bytes of a tcpdump or Wireshark capture.
| Seconds since 1900 | — |
|---|---|
| 64-bit hexadecimal | — |
| Era | — |
The NTP seconds counter is unsigned: it wraps to zero on 7 February 2036 at 06:28:16 UTC, the end of NTP era 0. A 32-bit field does not say which era it belongs to; for hexadecimal input, the converter applies the RFC 4330 convention: most significant bit set, era 0 (1968–2036); clear, era 1 (2036–2104). The full format is described in RFC 5905.
The year 2038 problem
A signed 32-bit integer stops at 2,147,483,647: the last representable second is 19 January 2038 at 03:14:07 UTC; the next one overflows and wraps around to 13 December 1901. 64-bit kernels and languages have solved this for themselves; it remains open wherever time is stored on 32 bits: file formats, protocols, old databases, embedded systems. The converter warns you when the date entered approaches or passes the limit.
Leap seconds
Unix time ignores them: it assumes 86,400-second days. International Atomic Time counts them: TAI − UTC = 37 s and GPS − UTC = 18 s since 1 January 2017, values confirmed by IERS Bulletin C 72 (6 July 2026). The converter gives the offset in force on the date entered, from the leap-seconds.list table, and claims nothing beyond its expiry. The history of leap seconds, what they broke and the future the CGPM has in store for them: the leap second, an operator's retrospective.
In your code
The examples use the timestamp being converted: 1792000000.
Shell (Linux, GNU date)
date +%s
date -u -d @1792000000macOS and BSD
date +%s
date -u -r 1792000000Python
import time
from datetime import datetime, timezone
time.time()
datetime.fromtimestamp(1792000000, tz=timezone.utc)JavaScript
Math.floor(Date.now() / 1000)
new Date(1792000000 * 1000).toISOString()PHP
time();
gmdate('c', 1792000000);MySQL / MariaDB
SELECT UNIX_TIMESTAMP();
SELECT FROM_UNIXTIME(1792000000); -- in the session time zone (time_zone)PowerShell
[DateTimeOffset]::UtcNow.ToUnixTimeSeconds()
[DateTimeOffset]::FromUnixTimeSeconds(1792000000).UtcDateTimeSee also
Paris and UTC to the second, corrected for your clock's offset. Check your machine's time
The NTP diagnostic for your browser. TOTP and NTP
Your 2FA codes are Unix time divided by 30.
Frequently asked questions
What is a Unix timestamp?
It is the number of seconds elapsed since 1 January 1970 at 00:00:00 UTC, the epoch, not counting leap seconds. Linux, macOS and most programming languages and databases represent an instant this way: a single number, the same in every time zone.
How can I tell whether a timestamp is in seconds or milliseconds?
By its length. For a date in our era, a timestamp has 10 digits in seconds, 13 in milliseconds, 16 in microseconds and 19 in nanoseconds. The converter detects the unit this way; you can force it for a very old or very distant date.
What is the year 2038 problem?
A timestamp stored in a signed 32-bit integer cannot exceed 2,147,483,647, which is 19 January 2038 at 03:14:07 UTC. One second later it overflows and wraps around to 13 December 1901. Systems that count on 64 bits are not affected; file formats, protocols and embedded systems that store time on 32 bits still are.
What is the difference between a Unix timestamp and an NTP timestamp?
The NTP timestamp counts from 1 January 1900, not 1970: you get it by adding 2,208,988,800 seconds to the Unix timestamp. It is 64 bits long, 32 for the seconds and 32 for the fraction of a second. Its seconds counter is unsigned and wraps to zero on 7 February 2036 at 06:28:16 UTC, at the end of NTP era 0; the protocol plans for this by numbering eras (RFC 5905).
Does Unix time count leap seconds?
No. Unix time assumes every day lasts 86,400 seconds: during a leap second, the counter repeats a second or smears it, depending on the system. TAI − UTC has been 37 seconds and GPS − UTC 18 seconds since 1 January 2017, values confirmed by IERS Bulletin C 72 of 6 July 2026.
Free NTP Tools
Three independent tools to diagnose your time synchronization: