Because time values are nothing more than a decimal extension of the date serial numbering system, you can add two time values together to get a cumulative time value. In some cases, you may want to add a set number of hours and minutes to an existing time value. In these situations, you can use the TIME function.
Cell D4 in Figure 4-20 contains this formula:
=C4+TIME(5,30,0)
In this example, you add 5 hours and 30 minutes to all the times in the list.
The TIME function allows you to build a time value on the fly using three arguments: hour, minute, and second.
For example, the following formula returns the time value 2:30:30 p.m.:
=TIME(14,30,30)
To add a certain number of hours to an existing time value, simply use the TIME function to build a new time value and then add them together. The following formula adds 30 minutes to the existing time, resulting in a time value of 3:00 p.m.
="2:30:00 PM" + TIME(0, 30, 0)