Date Difference Calculator AU
Find the number of days, weeks, months and years between two dates.
How it works
Enter a date of birth and an "as of" date to get exact age in years, months and days, plus the total in days and weeks.
Frequently asked questions
How many days are between two dates?
Enter both dates and the calculator counts the exact number of days between them, accounting for leap years and month lengths.
What is the difference between inclusive and exclusive counting?
Exclusive counts the days between (the nights); inclusive counts both endpoints, which adds one to the total.
Does it count leap days?
Yes. February 29 is included in any span that crosses it, keeping the count accurate.
Can it show the gap in weeks or months?
Yes. The difference can be expressed in days, weeks, months and years, though months vary in length so those figures are approximate.
Why do hotel nights differ from calendar days?
A stay touches more calendar days than nights — the 1st to the 4th is 3 nights but spans 4 dates — which is the inclusive-vs-exclusive distinction.
What can I use it for?
Counting down to events, measuring durations and ages, and tracking deadlines or project timelines.
Finding the gap between two dates
This calculator counts the time between two dates and shows it in days, and often in weeks, months and years too. It deals with leap years and varying month lengths automatically, so the count is exact rather than an estimate.
Worked example
From January 1, 2026 to March 1, 2026 is 59 days (January has 31 days and February 28 in 2026). Expressed differently that is about 8 weeks and 3 days, or roughly 2 months.
Inclusive vs exclusive counting
There are two ways to count: exclusive counts the nights between the dates (the usual "days between"), while inclusive counts both the start and end day, adding one. A hotel stay from the 1st to the 4th is 3 nights but touches 4 calendar days.
Date differences are handy for counting down to events, measuring ages or durations, tracking project timelines and figuring out how long ago something happened.
Results are estimates for general guidance in Australia and may not reflect the latest local rates, fees or rules. Check official sources before making decisions.