Quick answer
Elapsed counting measures the gaps between dates. Inclusive counting includes both listed dates, so it adds one to the elapsed count for a valid forward range.
Step by step
- Write the dates in chronological order. Decide whether you are counting the passage of days or calendar dates that are part of the range.
- Find the elapsed difference with the start date as day zero. Add one if the first and last dates both count.
- For weeks plus days, divide your chosen count by seven. Use whole weeks and the remainder.
Worked examples
A three-date window
Jan 1 to Jan 3 spans 2 elapsed days and includes 3 calendar dates.
A one-date window
Nov 9 to Nov 9 is 0 elapsed days and 1 inclusive date.
Cross February
Feb 28 to Mar 1, 2024 spans 2 elapsed days because Feb 29 is between them. The inclusive count is 3.
What to check
State which endpoints count whenever you share a number. This method counts dates, so changes to clock offsets do not alter the answer.
Related guides
Sources
See the calculation methodology or report an error.