Calculate the exact duration between two calendar dates and clock times with compound days, hours, and minutes.
Choose your starting calendar date and clock time (hours, minutes, AM/PM).
Choose your target concluding date and clock time.
Instantly view total elapsed days, hours, minutes, and compound duration (e.g. 3 days 6 hours 45 mins).
Total Seconds = (End Date/Time in UTC ms − Start Date/Time in UTC ms) ÷ 1,000 UTC ms = Coordinated Universal Time in milliseconds1,000 = Milliseconds per second conversion constantDays = floor(Sec ÷ 86400) | Hours = floor((Sec % 86400) ÷ 3600) | Minutes = floor((Sec % 3600) ÷ 60) 86400 = Seconds in a full 24-hour day3600 = Seconds in an hourStep-by-step breakdown of common real-world time scenarios, work shifts, and duration math.
Friday afternoon punch-out to Monday morning punch-in.
From Friday 5:00 PM to Monday 9:00 AM Tracking time from sprint start to release sign-off.
From Oct 1 09:00 AM to Oct 5 05:00 PM International multi-leg itinerary.
From Nov 12 11:30 PM to Nov 14 02:45 AM Measuring time duration between timestamps across multiple calendar days requires accounting for month lengths, leap years, and daylight saving shifts. If you only need calendar day counts or business day calculations without clock hours, use our Date Duration Calculator. For same-day or overnight shifts, use the flagship Time Duration Calculator or track daily employment hours with the Work Hours Calculator.
A compound duration expresses total elapsed time in decreasing units (Days, Hours, Minutes, Seconds). This is achieved via consecutive modulo divisions:
Total Days = Math.floor(Total Seconds ÷ 86,400)Remaining Seconds After Days = Total Seconds mod 86,400Hours = Math.floor(Remaining Seconds ÷ 3,600)Minutes = Math.floor((Remaining Seconds mod 3,600) ÷ 60)Convert both date-time points to UTC millisecond timestamps, calculate the difference, and convert the result into days (86,400 seconds), hours (3,600 seconds), minutes (60 seconds), and seconds.
From Friday 5:00 PM to Monday 9:00 AM is 64 total hours (2 days and 16 hours).
All calculations on this tool are deterministic and rigorously tested against base-60 modulo arithmetic and US Fair Labor Standards Act (FLSA 29 CFR § 785.48) payroll rounding guidelines.