I think I only need one If statement, but I always have fun with the semi-colons in Crystal formulas. I am never quite sure If and When I need to use the semi-colons where I have multiple command lines. Maybe there is a simple rule of thumb. Here's my simple code. Thanks!

WhilePrintingRecords;
NumberVar durat;
If {observe.date} in {?s_date} to {?e_date} then
    durat:=durat+VAL({observe.duration});
NumberVar totdurat;
If {observe.date} in {?s_date} to {?e_date} then
    totdurat:=totdurat+VAL({observe.duration});
NumberVar visit;
If {observe.date} in {?s_date} to {?e_date} then
    visit:=visit+1;
NumberVar totvisit;
If {observe.date} in {?s_date} to {?e_date} then
    totvisit:=totvisit+1;