Date arithmetic, with the awkward parts written down DATES
Three months from the 31st of January has no single answer, and two systems will give you two. Days between means two things, and people lose deadlines over it.
Between two dates
“Days between” means two things. A notice period counts the days that pass; a hotel booking counts the days involved. Both are here because the difference is one day and it is always the day that matters.
Which days are not working days
The list has to be yours. Public holidays differ by country, by region within a country, and by year, and any software that shipped a list would be wrong for most of the people using it.
Add to a date
Age
The working
How it works
DATES does date arithmetic and writes down the awkward parts. Three months from 31 January has more than one answer, and days between can mean two different things, so it shows both and says which rule it used. Add or subtract days, weeks, months and years, count business days, and see the reasoning behind every result. It runs in this tab.
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