I would like to get the time difference between two time values. One of the time values is stored in a varchar field in the HH24MI format. The other time value is stored as travel time in minutes to a particular location from location A. The location A is the location from where a journey originates and ends again in. So Travel Time * 2 will give me the total travel time and I add nother 1/2hr as buffer time. And then I minus the total Travel Time and buffer from the Time Value coulmn in the Table. This gives me the Time the journey is supposed to commence from the Location A. A typical Example will be
Time Value in the Table '2100'
Travel Time is 120 (this is in minutes)
So total Travel Time is 240 minute + 30 minutes = 270 Minutes which is 4.5 hrs. I need to minus this 4.5 hrs from 2100 and get the result 1630. Can anyone help me out with a qry for this.
Thanks in advance.