Developer / Date & time
Unix Timestamp Converter
Read an epoch value as UTC and local time, or turn a local date into seconds or milliseconds since January 1, 1970 UTC.
UTC versus local time
A Unix timestamp represents one instant, independent of time zone. The UTC result is stable everywhere. The local result uses the time zone settings of the browser running this page.
The reverse converter reads the value from the local date-time control as local time, then returns the corresponding UTC-based epoch number. Seconds discard the remaining millisecond fraction; milliseconds preserve it.