Days Between Dates Calculator

Pick two dates and the calculator counts the days between them. Calendar counting gives 14 days from 1 to 15 January 2026; including the end date makes 15; counting only Monday to Friday makes 10. Reversed dates are swapped, so the answer is never negative.

The page counts the days between two calendar dates, and the counting rule carries half the answer. Calendar counting is end minus start, a half-open span: the first day sits inside it, the last one is only the boundary. With the preset dates, 1 January 2026 to 15 January 2026, that comes to 14 days. Including the end date adds exactly one and gives 15. Working days keep only Monday to Friday out of the same span and give 10 — the four days of difference are the two weekends inside it. One span, three numbers, almost a third apart, purely from the rule you pick. Both dates become a running day number counted from 1 January 1970 UTC before they are subtracted, so no time of day, no time zone and no special case for a leap day appears anywhere. What the page does not do: it knows no public holidays, no half days and no working week other than Monday to Friday, and it answers in days only, never in weeks or months. The limit that matters most is what the number is worth afterwards. Both fields accept dates from 1 January 1900 to 31 December 2100, and for a legal deadline the plain day difference is a starting figure rather than the deadline itself: which day counts as the first, and what happens when the last one lands on a weekend, is written in the applicable law and not here.