ISO 8601 ↔ Epoch

ISO 8601 to Unix timestamp converter

Paste any ISO 8601 date string and instantly get the Unix timestamp — or go the other way and format a timestamp as ISO 8601 in any timezone.

ISO 8601 ↔ Epoch converter

Go both ways between ISO 8601 date strings and Unix timestamps.

ISO 8601 → Epoch

Enter ISO 8601 Date String

Example: 2025-08-02T12:00:00Z

Timezone

Unix seconds

–

Unix milliseconds

–

Normalized ISO (UTC)

–

Relative time

–

Epoch → ISO 8601

Enter Epoch Timestamp

Seconds or milliseconds, auto-detected. Example: 1754136000000

Timezone

ISO 8601 (UTC)

–

Local time

–

Detected unit

–

Relative time

–

Epoch → ISO 8601 (full converter)

The complete epoch to human-date converter, with timezone support.

Enter Unix Timestamp

Seconds or milliseconds — the unit is auto-detected. Example: 1735689600

Waiting for input…

Timezone

UTC ISO 8601

–

Local — auto

–

RFC 2822 / GMT

–

Seconds value

–

Relative time

–

What is ISO 8601?

ISO 8601 is the international standard for date and time representation. The basic format looks like 2025-08-02T12:00:00Z — the T separates the date from the time, and the trailing Z (or an offset like +02:00) marks the timezone.

How to convert ISO 8601 to epoch

Strip the offset (convert to UTC), then count the seconds since 1970-01-01T00:00:00Z. Most programming languages do this in one call: Date.parse() in JavaScript, datetime.fromisoformat() in Python, or strtotime() in PHP.

Timezone handling

A string like 2025-08-02T12:00:00+02:00 means 12:00 local time, two hours ahead of UTC — so the same instant as 10:00:00Z. Both convert to the same epoch value. When the offset is missing, ISO 8601 assumes local time; the converters above default to UTC in that case.

Convert other formats too: try the Excel date to Unix timestamp converter, or see code to parse ISO 8601 in JavaScript. Learn the basics in the Unix epoch time FAQ.