The HOUR function returns the number of hours in a time value.

• The syntax for the function is HOUR(serial_number) . The argument "serial_number" is the time value of which the umber of hours is extracted. Resulting in a value is between 0 and 23.
  
  

The "serial_number" can be in the form of a string, a decimal or the result of a formaula.
For example: HOUR("6:35:42") = 6 or when working with decimals HOUR(0.035) = 12 .This because 0.035 is interpreted as a "time value" representing a time of 12:50:24 AM and extracted a value of 12 hours.