This page provides a live reference for Unix seconds, milliseconds, UTC boundaries, and fixed values that recur in tests, logs, and database queries. Copy a boundary here, then use the converters when the input starts as a date or needs a named timezone.
Read the table as UTC
The live values above use UTC. A timestamp always identifies the same instant; only the rendered clock time changes across timezones. For a range query, prefer a lower boundary and the next boundary to an inclusive “last second of the day.”
WHERE created_at >= :start_of_day
AND created_at < :start_of_next_day
This half-open pattern works for seconds, milliseconds, and higher-resolution database values. It sidesteps the awkward question of how precise the last representable moment of a day should be.
Frequent questions:
- Q: Are Unix timestamp, Unix time, and epoch time the same thing?
- A: In most developer searches, yes. They all mean a numeric count from 1970-01-01 00:00:00 UTC, usually in seconds. Some systems use milliseconds, microseconds, or nanoseconds instead.
- Q: How do I convert timestamp to Unix time?
- A: If the timestamp is already a 10-digit epoch value, it is Unix time in seconds. If it is a date string, use the Date to Epoch converter. If it is a 13-digit value, divide by 1000 to get Unix seconds.
- Q: Where do I convert epoch to time?
- A: Use the Epoch to Time converter for the reverse direction: paste a Unix timestamp and get the readable date, UTC time, ISO 8601, and local timezone output.