Day Counter

Counting days between dates

The difference between two dates is the number of midnights between them. From Monday the 1st to Friday the 5th is four days by that measure; if you want to count the days themselves — the Monday through the Friday — that is five, and the 'include the end date' option adds the one. Which is right depends on the question: a hotel stay from the 1st to the 5th is four nights; a course that runs the 1st to the 5th is five days. The counter uses local midnight for both dates so daylight-saving changes cannot produce a 23- or 25-hour 'day'.

Countdowns to common dates from September 10, 2026:

Inclusive versus exclusive counting

Off-by-one errors are the commonest mistake in date arithmetic. Exclusive counting (the default) gives the gap; inclusive counting adds one for the end date. A full year from a date to the same date next year is 365 days exclusive and 366 inclusive; January has 31 days inclusive of both ends.

Weekdays, weekends and business days

Roughly five in seven days are weekdays, but the exact split depends on where the range starts. The counter lists weekdays (Monday to Friday), weekend days and business days — weekdays minus US federal holidays that fall on them. For adding business days to a date, or for other holiday sets, the business days calculator goes further.

Days in other units

The result also gives weeks and days, and the span in hours and minutes — 24 hours a day and 1,440 minutes, ignoring daylight-saving shifts, which the time duration calculator does account for. A year is 365 days (366 in a leap year), 52 weeks and 1 day (or 2).

Days from a date, and other date arithmetic

To find the date a number of days from today — 'what is 90 days from now' — use the date calculator, which adds or subtracts days, weeks, months and years. To find someone's age in years, months and days, the age calculator handles month lengths and leap years. This counter is for the simple, exact question: how many days lie between these two dates.

Weeks and months from a day count

Dividing days by 7 gives whole weeks with a remainder — 100 days is 14 weeks and 2 days. Months are not fixed, so the result's year-month-day line walks the calendar instead: 100 days from September 10, 2026 lands on December 19, 2026, which is 3 months and 9 days. Common conversions: 30 days is about a month, 90 days about three, 180 about six, 365 a year. For rough planning, a year is 52 weeks (plus a day or two) and a month is 4.35 weeks or 30.44 days.

Leap years and month lengths

Day counting needs no month-length rules: every date has a fixed day number and the difference is a subtraction. Leap days simply appear as one more day in the count — February 1 to March 1 is 28 days in most years and 29 in 2028. Months only complicate things when the question is 'how many months and days', which the year–month–day line in the result answers.