Unix Timestamp Converter

How to Use the Unix Timestamp Converter

1. Paste a timestamp into Timestamp to date. The unit is read from the number of digits and shown, and you can override it.
2. Choose the time zone you want to read the result in. The same instant is also shown in other zones below the result.
3. To go the other way, enter a date and time in Date to timestamp. If it has no offset, it is read in the selected time zone.
4. For a log or a list, paste it into Batch conversion.

Seconds, Milliseconds and How the Unit Is Read

A Unix timestamp counts time since 1 January 1970, 00:00:00 UTC, called the Unix epoch. Systems store it in different units, so the same moment can be written as 1700000000 (seconds), 1700000000000 (milliseconds), 1700000000000000 (microseconds) or 1700000000000000000 (nanoseconds).

With Auto, the unit comes from the number of digits, never from guessing:

• 1 to 10 digits: seconds
• 13 digits: milliseconds
• 16 digits: microseconds
• 19 digits: nanoseconds
• 11, 12, 14, 15, 17 and 18 digits could be either of two units. If only one reading is a date between the years 1 and 9999 it is used, and the page says so. If both are, you are shown both and asked to choose.

Numbers are handled exactly, with no rounding, so a 19-digit nanosecond value keeps every digit. A value with more precision than a nanosecond is refused rather than rounded.

Time Zones and Daylight Saving

A timestamp is one instant; a date and time on a wall clock only means something in a time zone. Zones are IANA names such as Asia/Kolkata or America/New_York, and their rules come from your browser.

Daylight saving can make a local time not exist (when clocks jump forward, such as 02:30 on the spring day in New York) or happen twice (when they go back). This tool says so instead of choosing for you: a skipped time gets no result and is explained, and a repeated time shows both instants, labelled earlier and later. Including an offset in the text, such as -05:00, fixes the instant and avoids the question.

Range, Leap Seconds and the Year 2038

Dates from the year 1 to the year 9999 are supported, including times before 1970, which are negative timestamps. Unix time counts every day as exactly 86,400 seconds, so leap seconds are not separate instants and are not modelled here.

The "year 2038 problem" affects software that stores Unix time in a signed 32-bit integer, which runs out at 03:14:07 UTC on 19 January 2038 (2,147,483,647 seconds). It is not a limit of timestamps in general: browsers and this tool use 64-bit values and carry on well past 2038.

Common Uses

• Reading an epoch from a log line, a database row or a webhook.
• Checking when a token or a cache entry expires.
• Telling seconds from milliseconds in an API field.
• Finding out what a local time is in another zone.

Timestamps often sit inside a JSON payload. To read the payload first, use the JSON Formatter & Validator.

Unix Timestamp Converter FAQ