PrismKitCalculatorsDuration CalculatorDuration CalculatorRuns in your browserLocalCopy linkMarkdownAdd and subtract durations like 1h 30m or 01:20:15, and find the time between two clock times.Date Add CalculatorAdd or subtract years, months, weeks, days, hours or business days from a date and get the weekday and ISO week.Week Number CalculatorFind the ISO 8601 and US week number, day of year and quarter for any date, or list the days of an ISO week.