Unix Timestamp Converter
Summary
Definition: Unix (POSIX) time counts non-leap seconds since the Unix Epoch.
Why it matters: Correct conversions prevent scheduling, logging, and data errors.
Pitfall: Milliseconds often appear as dates far in the future.
Unix timestamps are numbers, not dates. Identify the unit, convert to UTC,
and format only for human display to avoid errors.
- Epoch
- Reference time of 1970-01-01 00:00:00 UTC.
- POSIX time
- Seconds since the Epoch, ignoring leap seconds.
- Seconds
- Standard Unix timestamp unit.
- Milliseconds
- 1/1000 of a second, common in some APIs.
- UTC
- Global civil time standard.
Seconds vs milliseconds
Common mix-up: Unix time is not local time. Convert to local time only for display.
Unix time ignores leap seconds, unlike true UTC.
Quick example
Convert 1700000000 seconds to an RFC 3339 UTC date.
1700000000 -> 2023-11-14T22:13:20ZPractical insight
Unix timestamps are timezone-agnostic numbers. Formatting introduces time zones and calendars.
Try the converter
- Use the Unix Timestamp Converter.
- Verify the expected unit before converting.
Practical check
- Identify the timestamp unit.
- Convert to UTC first.
- Format only for display.
FAQ
How do I tell seconds from milliseconds? Seconds are often 10 digits, milliseconds 13, but always verify.
Why is my date near 1970? You likely treated milliseconds as seconds.
Is Unix time affected by time zones? No. Time zones apply only when formatting the output.