CalcCafe

UUID Timestamp Decoder

Extract the creation time embedded in a version-1 UUID. (v4 UUIDs are random and carry no time.)

Embedded timestamp (UTC)
Relative

Only version-1 (time-based) UUIDs carry a timestamp. v4 UUIDs are random and have none.

How it works

The tool reassembles the 60-bit time field from the UUID, divides by 10,000 to get milliseconds, and subtracts the 1582 Gregorian epoch offset.

Everything is computed locally in your browser — nothing is uploaded.

Frequently asked questions

Which UUIDs contain a time?
Only version-1 (and the related version-2) UUIDs embed a timestamp — 100-nanosecond intervals since 1582-10-15. Version-4 UUIDs are fully random and have no time.
How accurate is it?
The embedded clock is precise to 100 nanoseconds; this tool shows it to the millisecond.

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