Find the number of days, weeks and months between any two dates.
The gap between two dates can be expressed two ways, and they answer different questions. Total days is unambiguous: a straight count, useful for interest, notice periods and deadlines. Years, months and days is more readable but depends on a convention, because months vary in length. Counting from 31 January to 28 February can reasonably be called one month or twenty-eight days, and different tools resolve that differently.
The other decision is inclusivity. An exclusive count gives the days between the dates; an inclusive count includes both endpoints and is one larger. This sounds pedantic until it decides whether a contractual notice period, a hotel stay or a hospital admission is counted correctly. Legal and billing contexts often specify which applies, and when they do not, the assumption is worth stating explicitly. If the span crosses a daylight-saving transition, note that one day in the period is 23 or 25 hours long, which matters when the answer is needed in hours rather than days.
It depends on the purpose. An exclusive count gives the days between; an inclusive count includes both endpoints and is one greater. Contracts and billing rules usually specify which, and the difference genuinely matters for notice periods.
Because months vary in length, so a months-and-days breakdown depends on a convention for partial months. Total days is a plain count with no convention involved, which is why it is preferred where precision matters.
Not for whole days, but it does when the answer is needed in hours. One day in the period will be 23 or 25 hours where a transition occurs, so an hour-level calculation across that boundary needs care.
Subtract weekends and any applicable public holidays from the total. Holidays vary by country and often by state or region, so a working-day count is only as accurate as the holiday list applied to it.