Date Tools
Days Between Dates
Calculate the duration between two dates, expressed in multiple formats.
How it works
A precise day count, expressed every way you might need it: years/months/days, total months, weeks and days, and total days. Enter two dates by typing or with the dropdowns, and all four formats compute at once.
The “include end day” option adds one day to the count, for the situations — common in statutory deadline and accrual calculations — where both the first and last day count. The tool handles leap years and month-length differences correctly, which is exactly where mental arithmetic goes wrong.
Worked example
From March 15, 2024 to June 11, 2026 is 2 years, 2 months, 27 days — 26 months and 27 days — 116 weeks and 6 days — 818 days. With “include end day” checked, the total becomes 819 days.
When to use it
Use it for limitations math, computing ages of cases or claims, interest periods measured in days, or anywhere a brief says “X days later” and you want to verify rather than trust.
Frequently asked questions
When should I include the end day in a date calculation?
When the convention you're applying counts both endpoints — some statutes and contracts count the first and last day, others exclude the trigger day. The option adds exactly one day so you can match either convention. The governing rule (such as Federal Rule 6 or its state analog) decides which is right.
Why do the months-and-days and total-days figures look inconsistent?
Because months have different lengths, “2 months” from January 31 is not the same number of days as “2 months” from March 1. The tool computes each format independently and correctly; the total-days figure is the unambiguous one.
Does the calculator handle leap years?
Yes — leap days are counted like any other day, and February 29 is handled correctly in both directions.