Unix Timestamp Converter
Convert Unix timestamps in seconds or milliseconds to UTC, local time, ISO 8601 and selected IANA time zones, with automatic unit detection.
What this tool solves
Auto-detect Unix seconds or milliseconds and convert among local time, UTC, ISO 8601 and multiple IANA zones with relative time.
Input: a Unix timestamp in seconds or milliseconds, or a date/time to convert back when supported.
Output: human-readable dates in UTC/local time, ISO 8601 and selected time zones.
How to use it
- Paste the timestamp and confirm whether it is in seconds or milliseconds; the tool can help detect common lengths.
- Compare UTC with the intended local/IANA time zone rather than applying a fixed offset by hand.
- Copy the ISO or timestamp value only after verifying date, time and unit.
Common use cases
- Debug API timestamps and database values
- Convert log times into a local zone
- Compare seconds, milliseconds and ISO 8601 representations
Privacy, accuracy and limits
A timestamp is an instant, not a city time zone. Historical/future local display depends on IANA time-zone rules and daylight-saving changes.
WebToolMint keeps this workflow local in the browser where the feature allows it. Network-dependent tools are labelled separately. Keep originals and independently verify results that affect legal, financial, medical or business decisions.
Frequently asked questions
Why are some Unix timestamps 10 digits and others 13?
Modern timestamps in seconds are commonly around 10 digits, while milliseconds are commonly around 13. Always confirm the unit rather than relying only on length.
Does a Unix timestamp contain a time zone?
No. It identifies an instant relative to UTC; a time zone is applied only when displaying that instant as local time.
What is ISO 8601?
It is a standardized way to represent dates and times, often including a UTC marker or numeric offset.