Weeks Between Dates Calculator
How many weeks between two dates or until an event? See full weeks, leftover days and total days, using DD/MM/YYYY dates in either order.
Your results
Calculation breakdown
- Weeks
- floor(total days ÷ 7)
- Remainder
- total days mod 7
Worked example
From 01/01/2026 to 20/03/2026 is 78 days, which is 11 full weeks and 1 leftover day.
Assumptions
- Uses the exclusive elapsed difference: the start date is day zero and the following date is one day later.
- The order of the dates does not matter because the absolute difference is used.
- Uses whole calendar dates; time of day is ignored.
How this calculator works
This calculator takes the absolute elapsed calendar-day difference between two dates and splits it into complete 7-day weeks plus any remaining days. The count is exclusive of the start date, so consecutive dates are one day apart.
Frequently asked questions
How is a 'full week' defined?
A full week is any block of 7 consecutive calendar days; leftover days below 7 are shown separately.
Is the start date included in the count?
No. The result is the elapsed difference between the dates: the same date is zero days and the following date is one day. Add one only when your own counting rule includes both boundary dates.
Does it matter which date is first?
No, the calculator works out the absolute difference regardless of the order you enter the dates.
Content responsibility
Maintained by CalcAussie and last updated 13 October 2026. Checks applied: calculation method, worked examples, Australian terminology, material assumptions, official references where an external rule applies, and user-facing limitations.
Calculator results remain estimates based on the figures entered. Check material decisions against current official information and report a suspected error so it can be reproduced and corrected.