Runs locally in your browser
ISO 8601 Date & Time Converter
Parse an ISO 8601 value and inspect its UTC instant, Unix timestamps, source offset, local representation, and calendar details.
2026-09-01T08:30:00.000Z
1788251400
1788251400000
UTC (Z)
Tuesday
✓ Parsed locally in your browser
Read an ISO timestamp precisely
Paste a calendar date or date-time with an optional UTC designator or numeric offset. The normalized UTC result makes equivalent representations easy to compare, while Unix values are ready for APIs, databases, and logs.
Include an offset for portable timestamps
A date-time without an offset depends on the environment interpreting it. Prefer Z for UTC or an explicit numeric offset when storing or transmitting an instant between systems.
Frequently asked questions
What is ISO 8601?
ISO 8601 is an international date and time representation standard. A common internet form is 2026-09-01T08:30:00Z, where T separates the date and time and Z means UTC.
What is the difference between Z and a numeric offset?
Z represents UTC with zero offset. Values such as +08:00 and -04:00 describe local clock time at a fixed offset from UTC. Different representations can refer to the same instant.
What happens when an ISO date-time has no offset?
JavaScript interprets a date-time without Z or a numeric offset in the browser’s local time zone. Include an offset when the instant must be unambiguous.
Is the date sent to a server?
No. Parsing and conversion happen locally in your browser.