Loading…
Convert between epoch milliseconds (since 1970-01-01 UTC) and ISO 8601 date strings, both ways.
Sun Jun 21 2026 22:13:22 GMT+0900 (日本標準時)
Unlike the seconds-based Unix timestamp tool, this works in milliseconds (typically a 13-digit number). The output shows both the ISO 8601 UTC representation (YYYY-MM-DDTHH:mm:ss.sssZ) and your browser's local-time rendering of the same instant.
This tool is dedicated to millisecond values (typically a 13-digit number) and always emits ISO 8601 (YYYY-MM-DDTHH:mm:ss.sssZ). Use the existing Unix timestamp tool when you need seconds-based conversions or multiple display formats.
Yes. Anything Date.parse can interpret is accepted — e.g. 2024-01-01T00:00:00+09:00 or a trailing Z. Internally we normalize it to the corresponding millisecond value.
It uses your browser's configured time zone. The ISO 8601 view is always rendered in UTC (Z-suffixed), so comparing the two also makes the time-zone offset visible.