Explanation

Excel times are stored asfractional parts of one day.

For example, 12 hours is equal to 0.5, and 18 hours is equal to 0.75.

The trick is to first convert the Excel time to a decimal time by multiplying by 24.

Excel formula: Convert Excel time to decimal hours

This is the time format used in column B in the above example.

Excel formula: Convert decimal hours to Excel time

Excel formula: Extract time from a date and time