Elapsed versus calendar time
Elapsed time is what a stopwatch measures. Calendar time counts local days and months: from 12:00 on Saturday 9 March 2024 to 12:00 the next day in New York is one calendar day but only 23 elapsed hours, because clocks went forward overnight. Contracts, SLAs and medication schedules can mean either, so both are shown.
Business time
Business time counts only the parts of the interval that fall inside the working pattern you define, in the pattern’s own zone: start and end times (overnight allowed), a break, working weekdays and closed dates. No public-holiday data is bundled because holiday calendars vary by region and change often — add the dates that apply to you.
Date-only values
Birthdays and all-day deadlines are dates, not instants. Adding a month to 31 January needs a rule (use month end, or report an error); the date arithmetic panel asks for one and never involves a time zone.