Date Difference Calculator

Frequently asked questions

How is the difference in months and years calculated?

The years, months, and days breakdown is calendar based: it counts whole calendar years, then whole months, then the leftover days, so it matches how people read a date span. The total days figure is a straight count between the two dates, which is more useful for things like interest or notice periods.

When should I include the end date?

Include the end date when you want to count every calendar day as a full working unit, such as when calculating a notice period, a rental tenancy, or a leave entitlement where both the first and last day are counted. Exclude it for simple elapsed-time questions, such as how long ago an event happened, where the end day has not yet finished.

Why does the months figure differ from dividing days by 30?

Calendar months vary between 28 and 31 days, so dividing total days by 30 gives an approximate decimal that does not match how a lease or contract would count months. The calendar-accurate breakdown steps through actual month boundaries, which is why a span of 31 days might show as 1 month 0 days rather than 1.03 months.

Can I use this to calculate age?

Yes. Enter your date of birth as the start date and today as the end date. The years figure in the breakdown is your age in completed years, matching how age is stated on official documents. The remaining months and days tell you how far through the current year of life you are.