Time Calculator
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.
Add or Subtract Time from a Date
Time Calculator in Expressions
Use this calculator to add or subtract time values like 1d 2h 3m 4s + 4h 5s - 2030s + 28h.
Simplify Time Calculations – Fast, Accurate, and Efficient
Time plays a crucial role in our day-to-day lives—especially in fields like accounting, payroll, project management, and financial reporting. Whether you’re calculating billable hours, time differences, or adding/subtracting durations, our Time Calculator is designed to help you perform accurate time-based calculations in just a few clicks.
You can check our other calculators to calculate different things.
Why Use Our Time Calculator?
Unlike regular number calculations, time follows a unique format. Hours, minutes, and seconds don’t operate on a base-10 system like standard math. For example:
60 seconds = 1 minute
60 minutes = 1 hour
24 hours = 1 day
Our Time Calculator simplifies this complexity for you. With it, you can:
Add or subtract time units (e.g., 2 hours 45 mins + 1 hour 30 mins)
Convert between different time formats
Calculate time durations
Measure time passed or time remaining between two events
Time Units Covered
Here are the most commonly used units of time that our calculator supports:
| Unit | Definition |
|---|---|
| Millennium | 1,000 years |
| Century | 100 years |
| Decade | 10 years |
| Year | 365 or 366 days (leap year) |
| Month | 28 to 31 days |
| Week | 7 days |
| Day | 24 hours |
| Hour | 60 minutes |
| Minute | 60 seconds |
| Second | Base unit of time |
| Millisecond | 1/1,000 of a second |
| Microsecond | 1/1,000,000 of a second |
Time: A Quick Historical Perspective
The concept of time has evolved through centuries of scientific advancement and philosophical debate. From Aristotle’s ancient views on time as a measure of change, to Newton’s theory of absolute time, and later Einstein’s revolutionary idea of space-time relativity, our understanding of time has continuously expanded.
But for practical purposes—whether you’re calculating payroll cycles or setting financial deadlines—standardized time measurement matters most.
Modern timekeeping relies on two main tools:
Clocks – for measuring hours, minutes, and seconds
Calendars – for tracking days, weeks, months, and years
Our calculator combines both systems to offer accurate and easy-to-use functionality, ideal for business and personal use alike.
Fun Fact: Why 60?
Time is measured using the sexagesimal system—a base-60 system invented by the ancient Sumerians. Why 60? Because it’s divisible by many numbers (2, 3, 4, 5, 6…), making it easier to break down time into parts. That’s why:
1 hour = 60 minutes
1 minute = 60 seconds
This system is still in use today across clocks, angles, and geographical coordinates.
Who Can Use This Tool?
This tool is perfect for:
Accountants & Bookkeepers – calculating billing hours or time gaps in financial periods
HR & Payroll Teams – managing work hours, overtime, and shifts
Project Managers – tracking task durations or deadlines
Students & Researchers – converting and understanding historical or scientific time data
Everyone – who needs to calculate time accurately!
How to Use the Time Calculator
Select your operation – Add, Subtract, or Convert
Input the values – in hours, minutes, seconds (or higher units like days, weeks, months)
Get instant results – displayed clearly and accurately
Whether you’re working out how much time is left until a deadline or adding up total hours worked, this tool saves you time while calculating time.
Try It Now!
Use our Time Calculator today to eliminate the hassle of manual time math. Fast, simple, and precise—because every second counts!
