Unix Timestamp ↔ DateTime converter
Convert Unix timestamps in seconds or milliseconds to UTC ISO dates, or convert ISO DateTime back to Unix seconds.
Paste either format, then choose a direction.
Private · browser only
Your data stays in this browser. Nothing is uploaded.
Conversion directions
Direction 01
Unix Timestamp to DateTime
Detect Unix seconds or milliseconds and display an ISO 8601 UTC date.
Direction 02
DateTime to Unix Timestamp
Convert an ISO 8601 date and time into Unix seconds.
About this converter
Understanding Unix timestamps
A Unix timestamp counts the seconds that have elapsed since 1970-01-01 00:00:00 UTC, known as the Unix epoch. It is timezone-independent and used everywhere from databases and logs to cache headers and cron jobs. This converter detects whether your input is in seconds or milliseconds automatically.
Because the value is a plain number, timestamps sort naturally and avoid the ambiguity of localized date strings.
Converting in both directions
Paste a numeric timestamp to see the equivalent ISO 8601 UTC date and time, or paste an ISO 8601 date to get the Unix seconds back. Millisecond timestamps, common in JavaScript and Java, are recognised when the magnitude falls in the millisecond range.
Timezone and ISO 8601 notes
All conversions use UTC, the same reference as the Unix epoch. To display a local time, convert the timestamp in your application using its own timezone rules. ISO 8601 output includes the trailing Z to mark UTC explicitly.
Frequently asked questions
Does the timestamp converter accept milliseconds?
Yes. Large numeric values are automatically interpreted as milliseconds; shorter values are treated as seconds.
Which timezone is shown?
Timestamp results use UTC and the ISO 8601 format ending in Z.
What is the Unix epoch?
The Unix epoch is 1970-01-01 00:00:00 UTC. A Unix timestamp counts the seconds elapsed since that moment and is independent of timezones.
Does it detect seconds vs milliseconds?
Yes. The converter recognizes whether your input is in seconds or milliseconds based on its magnitude, which is useful for JavaScript and Java timestamps.
Which timezone is used?
All conversions use UTC, the same reference as the Unix epoch. The ISO 8601 output ends with Z to mark UTC explicitly.
Can I convert an ISO date back to a timestamp?
Yes. Paste an ISO 8601 date and time to get the equivalent Unix timestamp in seconds.