Unix timestamp converter and epoch time tool

What is a Unix timestamp?

A Unix timestamp is the number of seconds that have elapsed since 1 January 1970 at 00:00 UTC, known as the epoch. It is a compact, timezone-independent way to store a moment in time. Most systems use seconds, but JavaScript and many APIs use milliseconds, which is why a value can have 10 or 13 digits.

How to convert a Unix timestamp

1. 1 Paste a timestamp (seconds or milliseconds) or a date string.
2. 2 Read the ISO 8601, UTC, local and human-readable relative time.
3. 3 Pick a timezone to see the moment in any region, or build a date from individual parts.
4. 4 Use the difference and add/subtract tools for date math.

Common timestamp mistakes

• Seconds vs millisecondsA 10-digit value is usually seconds and a 13-digit value milliseconds. Mixing them shifts the date by decades.
• UTC vs local timeA timestamp is always UTC. Forgetting to convert to the local zone leads to off-by-hours bugs.
• The year 2038 problem32-bit signed timestamps overflow in 2038. Use 64-bit storage for far-future dates.