The HOUR function is a date and time function which returns the hour from zero to twenty-three from a valid time value.

This is the format of the HOUR function:

=HOUR(TIME VALUE)

Here is an example of the HOUR function:

=HOUR(43885.364) = 8 

This function is valuable when tracking information such as the start and end time of tests, tracking the timecards of employees who are paid hourly, or when analyzing traffic with timestamps to determine hourly requirements.

An example of a functional implementation of this would be tracking store traffic metrics against sales metrics, to see not only when your busiest times of day are, but when you are able to secure the best conversions. You would implement the HOUR function against your data to isolate the hour of occurrence to better analyze your results later.

=HOUR(C3)