Unix Timestamp Converter
Convert Unix timestamps and calendar dates.
Private by design
Your inputs stay on your device and are not sent to our servers. Optional usage analytics does not receive your files or tool inputs.
How to use Unix Timestamp Converter
- Paste a Unix timestamp and choose seconds, milliseconds, microseconds or nanoseconds. Auto detection uses digit count and can be wrong for old or unusual values.
- Select an IANA time zone or use UTC / My zone. Convert to UTC ISO time and the selected zone, with exact decimal timestamp values.
- For the reverse direction, enter a calendar date/time in the selected zone. Repeated or skipped DST times produce an error unless you explicitly select an earlier/later resolution.
What are the limits of Unix Timestamp Converter?
Unix time is based on the UTC epoch; zones change calendar display and interpretation of local date input, not the underlying instant. Decimal input is preserved to nanosecond resolution using integer arithmetic. Calendar fields support millisecond precision. Negative timestamps are accepted; exponent notation, leap-second notation and dates outside the Temporal range are rejected. Auto unit detection is heuristic, not validation. Time-zone history and future rules depend on browser/runtime data; Unix time does not count leap seconds. Expiry or scheduling decisions require application-specific validation.