Timestamp Converter

Unix timestamp

ISO 8601 / human-readable date

Could not convert

Enter a Unix timestamp to convert.

Quick answers

Does this tool account for daylight saving time?
Yes — timezone conversion uses the Intl.DateTimeFormat API with the IANA timezone database built into your browser, which correctly applies historical and current daylight saving rules for whichever timezone you select.
Why is my timestamp showing as 'out of range'?
JavaScript's Date object can only represent dates within about ±273,790 years of January 1, 1970. If you've entered a timestamp with too many digits (a common mistake is pasting a value in the wrong unit — nanoseconds instead of milliseconds, for example), it will fall outside that range.

About Timestamp Converter

Convert between Unix timestamps (seconds or milliseconds), ISO 8601 strings, and human-readable dates in any timezone your browser knows about. Handles negative (pre-1970) timestamps and flags values that fall outside a sane date range.

Unix time counts seconds (or milliseconds, depending on the system) since midnight UTC on January 1, 1970. It's timezone-agnostic by design — the number 1700000000 means the same instant everywhere on Earth, which is exactly why so many APIs and databases store time this way and leave timezone display as a formatting concern, not a storage one.

This tool treats both directions as first-class: type a Unix number and see it resolved to ISO 8601, RFC 2822, and your chosen timezone, or type a human-readable/ISO date and get the Unix number back out. Whichever field you last edited is treated as the source of truth for the conversion.

Negative timestamps (dates before 1970) are valid JavaScript dates and are supported here without special-casing — you'll just see a small note since it's an easy thing to mistake for a bug the first time you encounter it. Values far enough outside JavaScript's representable date range (roughly ±273,790 years from 1970) are rejected with an explanation rather than silently producing an 'Invalid Date'.

Frequently asked questions

Does this tool account for daylight saving time?

Yes — timezone conversion uses the Intl.DateTimeFormat API with the IANA timezone database built into your browser, which correctly applies historical and current daylight saving rules for whichever timezone you select.

Why is my timestamp showing as 'out of range'?

JavaScript's Date object can only represent dates within about ±273,790 years of January 1, 1970. If you've entered a timestamp with too many digits (a common mistake is pasting a value in the wrong unit — nanoseconds instead of milliseconds, for example), it will fall outside that range.

Can I convert a negative (pre-1970) timestamp?

Yes. Negative Unix timestamps represent dates before January 1, 1970 UTC and are fully supported — enter a negative number in the Unix field and it will resolve to the correct historical date.