Time Duration
Calculate Time Duration by entering start and end dates or times. Get precise durations in years, months, days, hours, and minutes.
Formula
Duration = End DateTime - Start DateTime
Calculate the difference between two date-time values in seconds, then convert to the desired units. Accounts for varying month lengths and leap years automatically.
Worked Examples
Example 1: International Flight Duration
Problem:A flight departs New York March 15 at 6:30 PM and arrives in London March 16 at 6:45 AM. What's the flight duration?
Solution:Start: March 15, 2024 at 18:30\nEnd: March 16, 2024 at 06:45\n\nFrom 18:30 to midnight: 5h 30m\nFrom midnight to 06:45: 6h 45m\n\nTotal: 5:30 + 6:45 = 12 hours 15 minutes\n\nNote: Actual local times differ due to timezone change (London is 5 hours ahead).
Result:12 hours 15 minutes (actual flight time)
Example 2: Project Timeline
Problem:A project starts January 15, 2024 at 9 AM and must be completed by March 31, 2024 at 5 PM. Calculate the available time.
Solution:Start: January 15, 2024 09:00\nEnd: March 31, 2024 17:00\n\nTotal duration:\n- Days: 76 (Jan 15-31 = 16, Feb = 29, Mar 1-31 = 31)\n- Plus 8 hours (9 AM to 5 PM)\n\nBusiness days (5/7): ~54 days\nBusiness hours: ~432 hours
Result:76 days, 8 hours | ~54 business days
Example 3: Event Countdown
Problem:Today is November 27, 2024 at 2:00 PM. The New Year's Eve event starts January 1, 2025 at 11:00 PM. How long until the event?
Solution:Start: November 27, 2024 14:00\nEnd: January 1, 2025 23:00\n\nNovember remaining: 3 days + 10 hours\nDecember: 31 days\nJanuary 1 to 23:00: 23 hours\n\nTotal: 35 days, 9 hours\n\n= 849 hours = 50,940 minutes
Result:35 days, 9 hours (849 hours)
Frequently Asked Questions
How do I calculate the exact duration between two dates and times?
Enter both the start and end date with their times. The calculator shows the exact duration down to the second, plus conversions to all common time units: seconds, minutes, hours, days, weeks, months, and years. It handles timezone-agnostic calculations.
Can I calculate duration across different time zones?
The current calculator treats all times as local time. For timezone-aware calculations, first convert both times to the same timezone (or UTC), then calculate the duration. The actual elapsed time is the same regardless of timezone.
What is decimal time and when is it useful?
Decimal time expresses duration as a single number (e.g., 8.5 hours instead of 8:30). It's useful for: payroll calculations, billing, spreadsheet formulas, and any mathematical operations on time. The calculator provides decimal hours and decimal days.
How do I convert between time zones?
Identify both time zones' UTC offsets and calculate the difference. EST is UTC-5, PST is UTC-8, so PST is 3 hours behind EST. Add hours when going east, subtract when going west. Online converters handle daylight saving time changes automatically.