What exactly is a Unix timestamp?

The number of seconds elapsed since 1970-01-01 00:00:00 UTC, deliberately ignoring leap seconds. It is timezone-neutral, which is why servers and APIs use it to exchange points in time.

Why does my timestamp convert to 1970 or throw an error?

You are probably mixing units: JavaScript Date uses milliseconds while many APIs return seconds. 1,700,000,000 is seconds (November 2023); 1,700,000,000,000 is milliseconds. This tool auto-detects the unit from its length.

How do I convert timestamps in my own code?

JavaScript: Math.floor(Date.now() / 1000) for seconds, new Date(ts * 1000) to convert back. Python: time.time() for seconds, datetime.fromtimestamp(ts, tz=timezone.utc) to convert back.

Time Utilities

Timestamp Converter

Convert Unix timestamps to date time and back.

Current time

---Milliseconds

---Seconds

Timestamp Converter

Timestamp → Date & time

Date & time → Timestamp