Unix Timestamp Converter
Convert Unix seconds or milliseconds to dates, and back.
How to use Unix Timestamp Converter
- Choose timestamp-to-date or date-to-timestamp conversion.
- For a timestamp, select seconds or milliseconds. For a date, select whether the input is local time or UTC.
- Read the UTC and local date, then copy the value you need.
What is Unix Timestamp Converter?
A Unix timestamp counts time from January 1, 1970 at 00:00:00 UTC. Many systems use seconds; JavaScript commonly uses milliseconds. The timestamp identifies an instant, while the displayed date depends on the time zone. This converter shows both UTC and your browser's local time.
- Timestamp-to-date and date-to-timestamp conversion
- Explicit seconds and milliseconds units
- UTC and local time output
- Copy results without uploading dates or timestamps
Separate an instant from its local display
1704067200 seconds and 1704067200000 milliseconds both identify midnight UTC on January 1, 2024. Selecting the wrong unit changes the represented instant. A 10- or 13-digit length is a clue for current dates, not a replacement for the producer’s field definition.
UTC and local output describe the same instant. A date-time with no offset is interpreted using the selected mode; local mode depends on this browser’s timezone and its daylight-saving rules. Use UTC or an explicit offset for examples that must reproduce on another device, and record the original unit with any copied value.
MDN: Date timestamps and timezone interpretationA practical example
1704067200 seconds
2024-01-01T00:00:00.000Z (UTC) 1704067200000 milliseconds
Learn a little more
Calendar days, date differences, and month-end arithmeticFrequently asked questions
How can I tell seconds from milliseconds?
Modern Unix timestamps are usually 10 digits in seconds or 13 digits in milliseconds, but digit length is only a clue. Check the system that produced the value and select its actual unit.
Why are the UTC and local dates different?
They describe the same instant using different time zones. Local time follows your browser's time zone, including daylight saving rules when applicable.
Can a Unix timestamp be negative?
Yes. A negative timestamp represents an instant before January 1, 1970 at 00:00:00 UTC, within the date range supported by the browser.
What does the Z at the end of a date mean?
Z indicates a UTC time with an offset of zero. For example, 2024-01-01T00:00:00.000Z means midnight at the start of January 1, 2024 in UTC.