Timestamp conversion
Unix Timestamp Converter
Detect seconds or milliseconds, show local time, UTC, and ISO 8601, or convert a date back to Unix time.
Local time follows this device’s time zone
Input
Timestamp or local time
Local time uses this device’s time zone; ISO output is always UTC.
Timestamp to date
Three views of the same instant
- Local time
- 11/15/2023, 06:13:20
- UTC / ISO 8601
- 2023-11-14T22:13:20.000Z
- Unix seconds
- 1700000000
- Unix milliseconds
- 1700000000000
Date to timestamp
Reverse conversion
1699999980seconds
How it works
A timestamp identifies an instant; time zones only change its display.
Unix time counts from 1970-01-01 00:00:00 UTC. Values around 10 digits are usually seconds; around 13 digits, milliseconds.
The same timestamp shows different clock times in Shanghai, Los Angeles, and London but represents one instant. A trailing Z in ISO 8601 means UTC.
Unix milliseconds = Unix seconds × 1000; the ISO 8601 Z suffix means UTC+00:00.
FAQ
Unix Timestamp Converter · FAQ
What is the difference between 10- and 13-digit timestamps?
Common 10-digit timestamps use seconds and 13-digit values use milliseconds. This tool detects them by absolute value.
Why do local time and UTC differ?
They display the same instant in different time zones. China Standard Time, for example, is normally UTC+8.
What is the Year 2038 problem?
Legacy systems storing seconds in signed 32-bit integers overflow in 2038. JavaScript Date is not bound by that same limit, though it has its own range.