Calculate difference between two dates

Today I had a cute requirement which is pretty small. The user want to see the time difference between two different time stamps.
Steps to do this
1) Create a column Date1 of DateTime
2) Create a column Date2 of DateTime
3) Create another column of Datatype Calculated type.
then enter the following formula in that column settings
=TEXT([DATE2]-[DATE1],"H:MM").

then you are done