How it works
The calculator counts the actual calendar days between your start and end dates, correctly handling months of different lengths and leap years. It also breaks the gap into weeks, an approximate number of months, and exact years/months/days, and counts the working days (Monday to Friday) in between.
Common uses
- Notice periods and project deadlines.
- Days until an exam, wedding, or due date.
- Leave, rent and interest periods.
Worked example
Take a start date of 1 April and an end date of 15 June in the same year. April contributes 29 remaining days, May contributes 31 and June contributes 15, giving 75 days — which is also about 10 weeks and 5 days, or roughly 2 months and 14 days.
The months figure is deliberately approximate. Calendar months are not equal in length, so "2 months and 14 days" is a description rather than an exact unit, while the day count is exact. When a contract or a deadline is written in days, use the day count and not the month figure.
Counting inclusively or exclusively
This is where most disputes about dates come from. "Within 30 days of 1 April" can mean the 30 days after the first, or the 30 days beginning on the first — a difference of one day, which is enough to miss a deadline.
- Gap counting (the default here) measures the distance between the two dates: 1 April to 2 April is one day.
- Inclusive counting counts both endpoints as days: 1 April to 2 April is two days. Turn on "Include the end date" for this.
- Interest and late fees are usually charged on the gap, so the day you repay is not normally charged.
- Notice periods and stays are more often counted inclusively. If it matters legally, check which the document means rather than assuming.
Frequently asked questions
Does it count both the start and end date?
By default it counts the gap (end minus start). Turn on "Include the end date" to count both days, which adds one.
Are weekends excluded from working days?
The working-days figure counts Monday to Friday only. It does not remove public holidays, which vary by state.
How are leap years handled?
Automatically. Any 29 February inside the range is counted, using the full rule — a year is a leap year if divisible by four, except centuries, unless divisible by 400.
Can I count backwards from a future date?
Yes. Put the later date in either field; the calculator reports the size of the gap regardless of which way round the two dates fall.
Does it work across different years?
Yes, including ranges spanning many years. Each year is counted at its correct length, so long ranges do not drift.