Date Math
"60 days from March 3, what day is it, and is it a Saturday?" The two-second answer this tool gives, with a weekday-counting mode.
Weekday mode = "N business days from" (US legal/contract counting: the day you start is day 0, delivery day counts; weekends skipped). Skipping-Sundays mode is the church/tradition count. Calendar mode is plain date arithmetic.
How the math works
- Calendar mode: straight UTC date arithmetic, every day counts, leap years handled by the calendar, not by a ÷365.25 shortcut.
- Weekday mode: day-by-day walk skipping Sat/Sun; "60 weekdays from Mar 3" lands ~84 calendar days out (12 weeks).
- Between mode: inclusive and exclusive counts are both printed, contracts say "from" (exclude start) and people say "between" (count ends both). Knowing which one your document means is the whole tool.
- Weekday row: because a deadline landing on Saturday is the whole reason this tool exists.
What is 30 days from a date?
Plain calendar arithmetic: March 3 + 30 = April 2. In weekday-counting (contract "days" that mean business days), 30 weekdays from March 3 lands April 14, the mode switch gives both answers.
How many days between two dates?
Between mode prints the exclusive count (not counting the start day, the Net-terms convention) and the inclusive count (both endpoints) so you match whichever your document uses.
Does the 30-day rule include weekends?
Depends on the document: "calendar days" includes weekends, "business days" skips Sat/Sun (and federal holidays, use the invoice tool for the holiday engine). Ambiguity is why the result row always shows the weekday.