How the days are counted
- Total days counts calendar days from the start date up to the end date — the start day itself is not counted, the end day is. August 31 to September 7 is 7 days.
- Weeks and days splits the total into whole weeks plus a remainder, so 38 days reads as 5 weeks and 3 days.
- Business days removes Saturdays and Sundays from the range. Tick the holiday option to also remove US federal holidays.
Counting forward to a deadline rather than measuring a span? The business days calculator adds N working days to a start date, and the invoice due date calculator applies Net 30, EOM and custom payment terms directly.
FAQ
How do I count the days between two dates?
Subtract the start date from the end date in days. From August 31 to September 7 there are 7 days: September 1, 2, 3, 4, 5, 6 and 7. The start day itself is not counted, the end day is.
Does the count include both the start and end date?
The standard convention — used here — excludes the start date and includes the end date. If both endpoints should count as elapsed days, add one to the total.
How many business days are in a year?
A common year has 365 days: 52 weeks plus one day, which averages 260 weekdays. After roughly 10 to 12 US federal holidays landing on weekdays, the real working year is about 248 to 250 business days.
How do I convert days into weeks?
Divide by 7 and keep the remainder: 38 days is 5 weeks and 3 days. The calculator shows this breakdown automatically next to the total.
Why does the day count matter for invoices?
Payment terms run in calendar days while delivery and correction windows often run in business days, so a Net 30 invoice issued just before a long weekend is not the same as one issued mid-week. Comparing both counts side by side shows exactly how much a holiday period shifts a deadline.
Does this calculator handle leap years?
Yes. February 29 is a normal calendar day here: the span from February 28, 2028 to March 1, 2028 is 2 days, and a full leap year contains 366 days.
Can I count backwards from an end date?
The count is direction-neutral — if the end date is earlier than the start date, swap them and the numbers are identical. For deadlines that start today and run forward in working days, use the business days calculator instead.