Time & Date
Time Calculator
Add or subtract hours and minutes from a start time and see if the result crosses midnight.
Educational estimates only. Not medical, legal, tax, or financial advice.
Guide: Time Calculator
What it does
Adds or subtracts a duration from a clock time, with midnight rollover shown clearly.
How to use it
Choose a start time, select add or subtract, enter hours and minutes, then read the final clock time.
Formula
Final minutes = start minutes +/- duration minutes, wrapped across 24-hour days.
Examples
23:30 + 2 hours = 01:30 next day. 00:15 - 30 minutes = 23:45 previous day.
FAQs
Can the result cross midnight?
Yes. The calculator shows whether the final time is on the same day, next day, or previous day.
Does this include dates?
No. This is a clock-time calculator. Use a date calculator if you need full calendar dates.
Can I subtract time?
Yes. Choose subtract, then enter the hours and minutes to move backward from the start time.