I have a formula in Crystal Reports that calculates a time interval based upon a condition. I was told by Crystal Reports tech support that I can't use the NumberVar method for my time result if I later want to sort the average times by group.

Here is my formula to calculate the time interval. What would I need to do to get rid of the formula and have Crystal Reports calculate the time interval for me so that I can sort on the average time interval for all members of the group?

If IsTime ({master.T_FA_ATPT}) and IsTime ({master.T_SHOCK}) and
  {master.shock_agcy} = "FD ALS" then
  NumberVar totsec:=(Time({master.T_SHOCK})-Time(0,0,0)) - (Time({master.T_FA_ATPT})-Time(0,0,0))
else
If IsTime ({master.T_FB_ATPT}) and IsTime ({master.T_SHOCK}) and
  {master.shock_agcy} = "FD BLS" then
  NumberVar totsec:=(Time({master.T_SHOCK})-Time(0,0,0)) - (Time({master.T_FB_ATPT})-Time(0,0,0))
else
If IsTime ({master.T_FA_ATPT}) and Not IsTime ({master.T_FB_ATPT}) and IsTime ({master.T_SHOCK}) then
  NumberVar totsec:=(Time({master.T_SHOCK})-Time(0,0,0)) - (Time({master.T_FA_ATPT})-Time(0,0,0))
else
If Not IsTime ({master.T_FA_ATPT}) and IsTime ({master.T_FB_ATPT}) and IsTime ({master.T_SHOCK}) then
  NumberVar totsec:=(Time({master.T_SHOCK})-Time(0,0,0)) - (Time({master.T_FB_ATPT})-Time(0,0,0))
else 0;