How can I subtract a time interval from another time interval

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C#

Oracle

Hi,

I have a table Table1 contain Fromdate and Todate Fields

Fromdate ToDate
--------- ---------------
12-FEB-15 01.30.59.000000 PM 12-FEB-15 04.30.59.000000 PM

i have another table Table2 it contain also fromdate and Todate fields.
Table2 must have the time in between of Table1 FromDate and TODATE.

Fromdate ToDate
--------- ---------------
12-FEB-15 02.00.59.000000 PM 12-FEB-15 02.30.59.000000 PM

Time difference -30 Mins

I want to show a list with remaining time (avoid 2 pm to 2.30 pm) like

1.30 P.M - 2.00 pm
2.30 P.M - 3.00 pm
3.00 P.M - 3.30 pm
3.30 P.M - 4.00 pm

How I get this list.

Please help me,

Thanks in advance ,

Vineeth@