Calculate difference between two dates?

[#1]

HI all,

I have two date fields, I have to calculate the difference in hours. viz., open date and close date.

Open_Date                  Close_Date

10/01/2016 08:20:00     12/01/2016 9:50:00

I used timestamp for both the columns and on the result also.

Eg: timestamp(Close_Date) - timestamp(Open_Date )  as Cycletime

Now i am getting the time in hours and minutes as below.

Eg: difference between abve dates is 49:30:00.

What I am expecting is like 49.50 hours(I have to calculate that 30 minutes into hours then add that to the 49 hours)

Thanks for any ideas.

regards

Prashanth

[#2]

I have used timestamp on two date columns and then subtracted, on result field again applied timstamp,

Its working.

[#3]

working when i appiled the timestamp separately on the date columns.