Free time difference calculator 2026. Calculate the duration between any two dates and times. See results in days, hours, minutes, total hours, and decimal hours. Perfect for project duration, age, and elapsed time tracking.
Enter the start date and time.
Enter the end date and time.
Click Calculate Time Difference to see days, hours, minutes, decimal hours, and total days.
Use this for project duration, age calculation, contract deadlines, and elapsed time tracking.
For business-day calculations (excluding weekends), use our Business Day Calculator.
Time difference is calculated by subtracting the start date-time from the end date-time in milliseconds, then converting to days, hours, minutes, and decimal hours. Days are 24h periods; decimal hours = total hours including fractional days. Useful for project duration, age, contract deadlines, and elapsed time tracking.
Start: Jan 1, 2026 9:00 AM. End: Mar 15, 2026 5:00 PM. Difference = 73 days 8 hours = 1,760h = 73.33 days. Useful for billing and milestone tracking.
Birth: Jan 15, 1990 8:30 AM. Today: Sep 22, 2026 noon. Difference = 13,408 days 3.5h = 321,792h = ~36.74 years. Precise age including time of day.
Contract signed: Sep 1, 2026. Delivery due: Nov 30, 2026. Difference = 90 days = 2,160h = 12.86 weeks. Standard 90-day delivery term.
Today: Sep 22, 2026 3:00 PM. Event: Dec 25, 2026 6:00 PM. Difference = 94 days 3h = 2,259h = ~13.4 weeks until Christmas.
Ticket opened: Sep 22 9:00 AM. Resolved: Sep 22 2:30 PM. Difference = 5h 30m = 5.5h. Within 8h SLA. If SLA is 4h, breach = 1.5h.
Find answers to the most common questions about time difference calculator.
Subtract the start date-time from the end date-time. The result is typically shown in days, hours, minutes, and decimal hours. Example: Jan 1 9:00 AM to Jan 3 5:00 PM = 2 days 8 hours = 56 hours = 2.33 days. Our calculator handles all date+time combinations and overnight spans.
For just days (no time), use a simple date subtraction: End Date - Start Date in days. Example: Jan 1 to Jan 31 = 30 days. Jan 1 to Dec 31 = 364 days. For business days excluding weekends, use our Business Day Calculator.
Age = (Today - Birth Date) / 365.25 (accounting for leap years). More precisely: count full years between dates. Example: born Jan 15, 1990. On Sep 22, 2026 = 36 years (since Jan 15 has passed). On Sep 22 before Jan 15 = 35 years. Use precise date arithmetic, not just /365.
No — this calculator uses local browser time. For time zone conversion (e.g., New York 9 AM to London time), use a dedicated time zone converter. The calculator treats both dates as the same time zone. If you need UTC-based calculation, convert both to UTC before entering.
Difference in hours = (End - Start) / 3,600,000 ms. Example: 9:00 AM to 5:30 PM same day = 8.5 hours. Across days: Mon 9 AM to Wed 5 PM = 56 hours. For decimal hours conversion needed for payroll, see our Payroll Hours Calculator.
Leap years add February 29 — 1 extra day every 4 years (except years divisible by 100 but not 400). 2024 and 2028 are leap years; 2100 is not. Date arithmetic automatically handles leap years when using standard date objects. Our calculator correctly accounts for leap years in all calculations.
Calculations and computational models on QuickBizCalc are verified against published regulatory standards and statutory tax tables:
Publication 15-T (Federal Income Tax Withholding Methods) & Publication 15 (Employer's Tax Guide).
Fair Labor Standards Act (FLSA 29 U.S.C. § 207) regulations on overtime hours, recordkeeping, and minimum wage.
OASDI taxable maximum wage base limits and statutory FICA tax rates (6.2% Social Security + 1.45% Medicare).
Formulas and worked examples are checked against the sources above before publishing. For advice on your own situation, consult a licensed tax professional or accountant.
Time Difference
30d 23h 59m
