WorldClock.lol

Time Calculator

Add or subtract hours and minutes, calculate duration between times, or convert time zones.

12:57:30 AMThursday, March 12, 2026

Add or Subtract Time

Result12:0012:00 + 0h 0m

Quick Time Calculations

Work Day Duration

9:00 AM to 5:00 PM = 8 hours

Half Day

9:00 AM to 1:00 PM = 4 hours

Lunch Break

12:00 PM to 1:00 PM = 1 hour

Night Shift

10:00 PM to 6:00 AM = 8 hours

How to Use the Time Calculator

1

Choose Calculation Type

Select Add/Subtract to modify a time, or Duration to find time between two points.

2

Enter Your Times

Input your starting time and the hours/minutes you want to add, subtract, or compare.

3

Get Instant Results

See the calculated result immediately. Works with times that cross midnight.

Common Uses for Time Calculator

Work Hours

Calculate total hours worked, overtime, or break durations.

✈️

Travel Planning

Add flight duration to departure time to find arrival time.

🍳

Cooking

Calculate when food will be ready based on cooking time.

📅

Event Planning

Figure out end times for meetings, appointments, or events.

Frequently Asked Questions

How do I add hours to a time?

Enter your starting time in the input field, make sure "Add" is selected, then enter the number of hours and minutes you want to add. The result will update automatically. For example, adding 3 hours to 10:00 AM gives you 1:00 PM.

How do I calculate the duration between two times?

Switch to "Duration Calculator" mode, enter your start time and end time, and the calculator will show you the total hours and minutes between them. It automatically handles times that cross midnight (e.g., 10 PM to 6 AM = 8 hours).

Can I calculate time across midnight?

Yes! The time calculator handles times that cross midnight automatically. If you add 10 hours to 8:00 PM, it will correctly show 6:00 AM. The duration calculator also works across midnight— 10:00 PM to 2:00 AM correctly calculates as 4 hours.

How do I subtract time?

Click the "Subtract" button in the Add/Subtract mode, then enter the hours and minutes you want to subtract. For example, subtracting 2 hours from 10:00 AM gives you 8:00 AM. Subtracting past midnight wraps to the previous day (e.g., 1:00 AM minus 3 hours = 10:00 PM).