Advanced date and time calculationsElapsed time with zones, clock differences, averages, sorting and interval splitting.
Details of the first result
Dates & time
How it works
A date sequence starts with an anchor and applies a step. Calendar stepping is not the same as adding fixed seconds: months change length, and calendar dates have no time zone.
What you can do
Generate date ranges, monthly schedules, clock times or exact Unix timestamp sequences.
How to use it
- Choose calendar dates, clock times, or Unix timestamps. Set a start, step, and result count. Calendar dates also support an inclusive end date and weekday filters. Choose original-start or cumulative month stepping, then calculate.
- For date or clock sequences, optionally enter bracketed output tokens. Leave the template blank to keep ISO output; unknown tokens are rejected.
- Check the result and its notes. Copy or download only after calculating; any edit clears the old result.
Errors and limits
At most 10,000 results and 100,000 candidate dates. Date steps must be nonzero and point toward the end. Date filtering uses Monday–Friday / Saturday–Sunday without holidays. Clock times wrap at 24 hours. Timestamp step uses the selected input unit.
All input stays in this tab. TXT files must be UTF-8; bulk input is limited to 200,000 characters and 10,000 lines.
Extensions: year searches ≤500years; date patterns ≤200,000days; clock patterns ≤24hours; result ≤10,000rows. Magic digits mean all equal or ascending with9→0 wrap. Choose the digit representation explicitly. Rounding ties choose the later boundary; ISO weeks start Monday. Date templates: [YYYY] [MM] [DD] [DDD] [W] [E]; clocks: [HH] [hh] [mm] [ss] [A]. Natural-language output uses your interface language. Gregorian Easter:1583–4099. Interval input: start / end.
Frequently asked questions
How do I keep a monthly sequence on the 31st?
Choose anchor to the starting date and last valid day. From Jan31 2024, the results are Jan31, Feb29, Mar31. Cumulative stepping instead returns Jan31, Feb29, Mar29 because it adds to the previous result.
Are my dates uploaded or saved?
No. These calculations run in your browser. Inputs are not added to the address, stored between visits or sent to a server. Copy and download save only when you ask.