A Unix timestamp counts elapsed time from 1 January 1970 at 00:00:00 UTC. QR64Code treats typical 10-digit values as seconds and 13-digit values as milliseconds, then displays both UTC and local time.
What changed in this update?
July 30, 2026
The tool, explanation, limits, sources, and accessible form flow were reviewed together.
How to use it
- 1
Enter a Unix value or a date.
- 2
Check the detected unit.
- 3
Copy the UTC, local, or ISO 8601 result.
Limits and security notes
Local output depends on the device time zone. Prefer ISO 8601 UTC when moving data between systems.
Comparison
| Format | Typical length | Time zone |
|---|---|---|
| Unix seconds | 10 digits | UTC-based |
| Unix milliseconds | 13 digits | UTC-based |
| ISO 8601 | 2026-07-22T…Z | Z means UTC |
Frequently asked questions
What is the difference between 10 and 13 digits?
Ten digits usually mean seconds, while 13 digits provide millisecond precision.
Does a Unix timestamp contain a time zone?
No. It represents elapsed time from the UTC epoch.
What is the Year 2038 problem?
Signed 32-bit second counters can overflow in 2038; modern JavaScript dates do not share that exact storage limit.