Standard Formats

ISO 8601 ↔ Unix Timestamp Converter

Paste any ISO 8601 date string and instantly calculate its Unix timestamp — or go the other way and format an epoch timestamp as an ISO 8601 string in any timezone.

ISO 8601 → Unix Epoch

Paste any standard ISO 8601 or RFC 3339 string

Enter ISO 8601 Date String

Example: 2026-10-02T12:00:00Z or 2026-10-02T14:00:00+02:00

Timezone (If offset omitted)

Unix Seconds:–

Unix Milliseconds:–

Normalized UTC ISO:–

Relative Time:–

Unix Epoch → ISO 8601

Convert seconds or milliseconds to ISO 8601 representation

Enter Epoch Timestamp

Timezone Format

UTC ISO 8601:–

Local Formatted Date:–

Detected Magnitude:–

Relative Time:–

What is ISO 8601?

ISO 8601 is the international standard covering the exchange of date and time-related data. The basic format follows YYYY-MM-DDTHH:mm:ss.sssZ, where:

T is the delimiter separating the date components from the time components.
Z stands for the Zulu timezone (UTC +00:00).
Offsets such as +05:30 or -04:00 denote the deviation from UTC.

How to Parse ISO 8601 in Code

In modern JavaScript/TypeScript, calling Date.parse("2026-10-02T12:00:00Z") automatically parses UTC and returns the Unix millisecond timestamp. In Python, you can use datetime.fromisoformat("2026-10-02T12:00:00+00:00") to construct a timezone-aware datetime object.