How the Day Counter works
Each Civil Date becomes an integer day index in the proleptic Gregorian calendar. The ordered difference gives a Calendar-day Interval. Full seven-day blocks contribute five Weekdays and two Weekend Days; at most six remaining dates are classified individually.
Examples you can reproduce
- Adjacent dates count as 1 day when the end is excluded, or 2 when it is included.
- Equal dates count as 0 by default, or 1 with Included End Date.
- 1900 is not a leap year; 2000 is a leap year under the 4/100/400 rule.
- Every complete seven-day interval contains exactly 5 Weekdays and 2 Weekend Days.
Limits and assumptions
Weekday means Monday through Friday. Weekend Day means Saturday or Sunday. Holidays and regional work calendars are intentionally not included.
Frequently asked questions
Is the end date included?
Not by default. Turn on Included End Date to count both endpoints. The result repeats the active rule.
Are weekends included?
Yes. Total calendar days include every date; Weekdays and Weekend Days are shown separately.
Does it use 24-hour timestamp differences?
No. It compares Civil Dates directly, so timezone and daylight-saving changes cannot alter the count.