Timestamp Range Generator
Start and end of the day, ISO week, month, quarter and year around an instant at a UTC offset — ISO 8601 and epoch, inclusive and exclusive — plus period lists.
Five period ranges with inclusive and exclusive ends ready for query predicates, and a list of consecutive periods between two instants for partitions, reports or backfills.
Example: 2026-09-20T10:00Z: day 1789862400 – 1789948800, ISO week 2026-W38 from Monday 14 Sep, month 2026-09, Q3, 2026; at UTC+07:00 the day starts 7 h earlier in epoch terms and each boundary shifts.
Boundaries on the wall clock,
values on the epoch.
How the boundaries are found, what inclusive and exclusive mean, and the DST caveat.
Boundaries
The instant is shifted by your UTC offset to a wall-clock date, the period boundaries are found there (midnight, the Monday of the ISO week, the first of the month or quarter, 1 January) and shifted back to true instants. Every boundary is given as ISO 8601 in the offset, Unix seconds and milliseconds.
Inclusive and exclusive
A period’s exclusive end is the start of the next one — the right value for "≥ start AND < end" predicates. The inclusive end is one millisecond earlier, for systems that compare with ≤. Using the inclusive end with millisecond-precision data can miss the last millisecond; the page shows both so you can pick.
Fixed offset
The offset is fixed for the whole calculation. A zone with daylight-saving time changes its offset during the year, so a period spanning the change has a boundary one hour off in wall-clock terms; the page has no tz database and says so rather than guessing. Nothing leaves the browser; the same four anonymous usage counts as the rest of the site apply.
SOURCES
- ISO 8601 week dates (weeks start Monday; week 1 holds the first Thursday); Unix epoch seconds; boundaries computed at a fixed UTC offset — no tz database, DST caveat stated
Last reviewed 20 September 2026. How results are checked: How we verify.