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Add Hours Calculator

Add or subtract hours from any time of day. Enter a start time and number of hours (decimals OK) to find the resulting time, with automatic midnight wraparound.

How to Add Hours to a Time

Convert the start time to total seconds, add the hours (in seconds), then convert back to HH:MM:SS.

• Example: 9:00 AM + 8 hours = 5:00 PM

• Example: 10:30 PM + 4 hours = 2:30 AM (wraps past midnight)

Decimal hours are supported: 1.5 hours = 1 hour 30 minutes.


See also