Days Between Dates Calculator

Practical uses and edge cases

Counting days is common for notice periods, loan interest, visa stays, project deadlines and age checks. Many contracts state whether the first and last days are included, so read the wording before relying on a number. For interest on a deposit, banks usually count the day the money arrives but not the day it is withdrawn.

Leap years add a 29 February every four years, except century years not divisible by 400, so 2000 was a leap year but 1900 was not. Between 1 January 2024 and 1 January 2025 there are 366 days because 2024 is a leap year. Time zones rarely matter for whole-day counts, but they can matter if you compare timestamps close to midnight.

How the day count works

The calculator converts both dates to a day number and subtracts them, so month lengths and leap years are always handled correctly. By default the start date is not counted and the end date is, which matches how most people count "days until" or the number of nights in a stay. If you need inclusive counting (both the first and last day), add one day.

Results are also shown in weeks and days, which helps with notice periods, project schedules and medication courses.

Worked example

From 1 January 2026 to 1 March 2026: January has 31 days and February 2026 has 28, so the difference is 59 days, or 8 weeks and 3 days. Counted inclusively (both 1 January and 1 March), it is 60 days. Over 1 January 2024 to 1 March 2024 the answer is 60 days because 2024 was a leap year.

Business days

Contract and banking deadlines often count working days only. For those, use the business days calculator, which skips weekends; public holidays differ by state and country, so check them separately.