This calculator can be used to 'add' or 'subtract' two time values. Input fields can be left blank, which will be taken as 0 by default.
Use this calculator to add or subtract time (days, hours, minutes, seconds) from a starting time and date. The result will be the new time and date based on the subtracted or added period of time. To calculate the amount of time (days, hours, minutes, seconds) between times on two different dates, use the Time Duration Calculator.
Use this calculator to add or subtract two or more time values in the form of an expression. An acceptable input has d, h, m, and s following each value, where d means days, h means hours, m means minutes, and s means seconds. The only acceptable operators are + and -. "1d 2h 3m 4s + 4h 5s - 2030s" is an example of a valid expression.
Effortlessly manage time calculations with our Time Calculator. Add or subtract hours, minutes, or seconds, and convert between units like days or weeks. Perfect for scheduling, payroll, or tracking durations, it handles complexities like leap seconds and time zones with precision.
A Time Calculator is an online tool that simplifies time arithmetic and unit conversions. Unlike regular numbers, time calculations require handling unique rules, delivering results like:
It converts time to a base unit (like seconds), performs the operation, and outputs results in your chosen format, respecting rules like 60 minutes per hour.
Example:
Add: 3 hours 20 minutes + 2 hours 50 minutes
Result:
Total: 6 hours 10 minutes
In Minutes: 370 minutes
In Seconds: 22,200 seconds
Instantly view:
✔ Total time added or subtracted
✔ Converted units (e.g., hours to minutes)
✔ Detailed breakdown in your preferred format
Q1: Can it handle time zone differences?
✅ Yes, select the time zone option for accurate results.
Q2: Does it account for leap seconds?
✅ Yes, it adjusts for precise timekeeping.
Q3: Can I convert hours to days or minutes?
✅ Yes, the tool supports multiple unit conversions.
Q4: Is it useful for payroll calculations?
✅ Absolutely, it calculates exact work hours or shifts.
Q5: Can it add or subtract large time spans?
✅ Yes, it handles everything from seconds to days seamlessly.
Whether managing work schedules, planning travel, or tracking project durations, our Free Online Time Calculator delivers quick, accurate results. Skip the hassle of manual calculations and get precise time math instantly.
🚀 Try it now to simplify your time calculations!
Time calculations differ from regular math due to their unique structure, requiring careful handling of units like seconds, minutes, and hours.
| Unit | Definition |
|---|---|
| millennium | 1,000 years |
| century | 100 years |
| decade | 10 years |
| year (average) | 365.242 days or ~12 months |
| common year | 365 days or 12 months |
| leap year | 366 days or 12 months |
| quarter | 3 months |
| month | 28-31 days Jan, Mar, May, Jul, Aug, Oct, Dec: 31 days Apr, Jun, Sep, Nov: 30 days Feb: 28 days (common year), 29 days (leap year) |
| week | 7 days |
| day | 24 hours or 1,440 minutes |
| hour | 60 minutes or 3,600 seconds |
| minute | 60 seconds |
| second | Base unit of time |
| millisecond | 1/1,000 second |
| microsecond | 1/1,000,000 second |
| nanosecond | 1/1,000,000,000 second |
| picosecond | 1/1,000,000,000,000 second |
Early civilizations, like the Greeks, viewed time as a measure of change. Philosophers like Aristotle (4th century BC) described time as linked to motion, suggesting it’s a way to track the sequence of events. He saw time as continuous and infinite, raising questions about its existence without change.
In the 17th century, Newton proposed time as an absolute, flowing independently of events, measured mathematically as “duration.” Conversely, Leibniz argued time only exists relative to objects and events, serving as a framework for sequencing and comparison.
Albert Einstein’s theory of relativity (early 20th century) revolutionized time concepts, linking it with space into “spacetime.” He showed that time varies with speed and gravity, with the speed of light remaining constant for all observers, altering how we perceive duration.
Modern timekeeping uses calendars and clocks, rooted in the base-60 system from ancient Sumerians (3rd millennium BC). This system, adopted by Babylonians, leverages 60’s divisibility for precise subdivisions of hours and minutes.
Ancient Egyptians pioneered dividing the day using sundials, splitting daylight into 12 parts. By 147-127 BC, Hipparchus, a Greek astronomer, formalized the 24-hour day, balancing 12 hours of day and night during equinoxes.
Ancient cultures used varied devices like water clocks (clepsydras) for accuracy in time division. The first mechanical pendulum clock, invented by Christiaan Huygens in 1656, marked a leap in precise time measurement.
This content is independently researched and authored by me, based on historical and scientific principles of time measurement.