About the Unix Timestamp Converter
This Unix timestamp converter translates epoch time — the number of seconds since 00:00:00 UTC on 1 January 1970 — into a readable date, and converts any date and time back into a timestamp. Paste a value from a log file, database column, JWT exp claim or API response and it detects whether it is in seconds, milliseconds or microseconds, then shows it as ISO 8601, as an RFC 1123 HTTP date, and in the UTC offset you choose.
Developers, data analysts and support engineers use it to decode created_at fields, check token expiry times, schedule cron jobs and line up events across time zones. The reverse mode takes a calendar date, a time and a UTC offset (for example −5 for US Eastern Standard Time or 5.5 for India) and returns the exact seconds and milliseconds to paste into code or a query.
Unix time ignores leap seconds and is always based on UTC, so the same timestamp represents the same instant everywhere — only the displayed wall-clock time changes with the offset. Offsets are entered manually rather than read from your device, so results are reproducible and daylight-saving rules never shift them silently.
How to use the unix timestamp converter
- 1Choose Timestamp → date or Date → timestamp.
- 2Paste the epoch value (seconds, milliseconds or microseconds), or pick a date and time.
- 3Set the UTC offset for the time zone you care about.
- 4Copy the ISO 8601, HTTP date, seconds or milliseconds value you need.
Formula and method
Unix time counts the seconds elapsed since the epoch, 00:00:00 UTC on 1 January 1970, treating every day as exactly 86,400 seconds (leap seconds are ignored). To convert a timestamp to a date, the value is scaled to milliseconds, added to the epoch and split into calendar fields in UTC; the chosen offset is then added to show the local wall-clock time.
In auto mode the unit is inferred from the digit count: up to 11 digits are seconds, 12–15 are milliseconds and 16 or more are microseconds, which covers present-day dates. For date → timestamp, the entered local date and time minus the UTC offset gives the UTC instant, so 09:30 at UTC−5 becomes 14:30 UTC.
- timestamp
- Seconds since 1970-01-01 00:00:00 UTC
- offset
- Hours ahead of (+) or behind (−) UTC
Worked examples
Timestamp 1767225600
1,767,225,600 seconds after the epoch is exactly midnight UTC on 1 January 2026, a Thursday. The same instant in milliseconds, as JavaScript’s Date.now() would report it, is 1767225600000.
Millisecond timestamp shown in India (UTC+5:30)
The 13-digit value is detected as milliseconds. In UTC it is 22:13:20.123 on Tuesday 14 November 2023, but adding 5 hours 30 minutes pushes it past midnight to 03:43:20 on Wednesday 15 November in India.
Date to timestamp: 4 July 2026, 09:30 US Eastern (UTC−5)
09:30 at UTC−5 is 14:30 UTC. That instant is 1,783,175,400 seconds after the epoch. (In July US Eastern is on daylight time, UTC−4 — enter −4 to use that instead.)
The Year 2038 limit
2,147,483,647 is the largest value a signed 32-bit integer can hold. As a Unix time it is 03:14:07 UTC on Tuesday 19 January 2038; one second later, 32-bit systems overflow to 1901.
Frequently asked questions
What is a Unix timestamp?+
A Unix timestamp (epoch time or POSIX time) is the number of seconds since 00:00:00 UTC on 1 January 1970, not counting leap seconds. It is a single number that identifies the same instant in every time zone.
How do I tell if a timestamp is in seconds or milliseconds?+
Count the digits. Current dates are 10 digits in seconds (e.g. 1767225600) and 13 digits in milliseconds (1767225600000). JavaScript and Java usually use milliseconds; Unix tools, Python time.time() and many REST APIs and JWTs use seconds.
Does a Unix timestamp have a time zone?+
No. It always counts from the epoch in UTC. Time zones only matter when you display it as a calendar date and time, which is why this tool lets you choose the UTC offset for the display.
What is the Year 2038 problem?+
Systems that store Unix time in a signed 32-bit integer can only count to 2,147,483,647, which is 03:14:07 UTC on 19 January 2038. After that the value overflows. Modern 64-bit systems are not affected.
How do I get the current Unix timestamp in code?+
JavaScript: Math.floor(Date.now() / 1000). Python: int(time.time()). PHP: time(). Bash: date +%s. SQL (PostgreSQL): extract(epoch from now()). Each returns seconds except Date.now(), which returns milliseconds.