Unix Timestamp Converter

How to use

1. Timestamp → Date: paste a Unix timestamp into the left box and click Convert. Seconds (10 digits) and milliseconds (13 digits) are detected automatically.
2. Date → Timestamp: pick a date and time on the right and click Convert to get both the second and millisecond values.
3. Click Use current time to work with the present moment.

Use cases

1. Use case: Debug logs Convert a Unix timestamp from application logs into a readable date to correlate events.

2. Use case: Work with databases Translate between epoch milliseconds and human dates when reading API responses or DB columns.

Practical tips

The classic bug is seconds versus milliseconds: JavaScript's Date.now() returns milliseconds, while most backends and APIs use seconds — a ten-digit timestamp is seconds, a thirteen-digit one is milliseconds. Convert to a timezone explicitly; the tool shows UTC and your local zone side by side so a date rollover never surprises you. ISO 8601 output is the safest form to store, since it is unambiguous about order and timezone. Like every tool on this site, the Timestamp Converter runs entirely in your browser: the data you enter never leaves your device, nothing is uploaded to a server, and the tool keeps working if your connection drops.

Common mistakes

Timestamp bugs are almost always unit or timezone mistakes:

• Confusing seconds and milliseconds: a ten-digit timestamp is seconds, a thirteen-digit one is milliseconds — JavaScript's Date.now() returns milliseconds while most backend APIs use seconds.
• Reading a UTC result as local time (or the reverse) and concluding the data is wrong by several hours.
• Ignoring date rollover: an evening timestamp in one zone is often tomorrow morning in another.
• Storing local time instead of ISO 8601 in databases, which breaks the moment a server or user changes timezone.

Frequently asked questions