Timestamp Converter
Convert between Unix timestamps and human-readable dates in multiple formats
💡 Unix timestamp is the number of seconds since January 1, 1970 (UTC) · All processing is done locally in your browser
About This Tool
Unix timestamps are the universal language of time in computing — the number of seconds since January 1, 1970 (UTC). This free online timestamp converter handles bidirectional conversion between timestamps and human-readable dates with ease.
Key use cases include debugging JWT token expiration times, converting database timestamps from logs, working with API responses that use epoch time, calculating time differences between events, and generating timestamps for cron jobs or scheduled tasks.
The tool automatically detects whether your input is in seconds or milliseconds (a common source of bugs), provides multiple date format outputs, and includes a "Now" button to quickly insert the current timestamp. All parsing is done client-side with zero latency.
How to Use
- Paste a Unix timestamp — the tool auto-detects seconds versus milliseconds.
- Or pick a date and time, then convert in the opposite direction.
- Use the Now button to grab the current timestamp instantly.
- Copy any of the formatted outputs for your code or config.
Tip: A ten-digit timestamp is in seconds; thirteen digits means milliseconds. That single check prevents most bugs.
Common Mistakes
1. Mixing seconds and milliseconds
Passing a millisecond value to an API that expects seconds puts you in the far future. Count the digits before you convert.
2. Ignoring time zones
Unix timestamps are always UTC. The same instant prints different local dates in Tokyo and New York — store timestamps, convert only for display.
3. Ambiguous date strings
Parsing a date-only string in JavaScript yields different results depending on format, because the spec treats date-only forms as UTC midnight. Be explicit about the zone.
4. Zero-based months
When constructing dates manually in JavaScript, month numbering starts at zero. January being month one is the classic off-by-one crash.