Date not cycling with addition of time

Trying to figure out issue with adding date and time.
The code is listed below.
I have watched the code while running. The initial date FDateS and FDate(t) value is m/dd/yyyy (9/16/2010) and no time. FDateS has different amounts of time added to it. The issue I have encountered is that once it passes midnight, the date does not change but the time reflects the change to 00:00:00.

Public FDate(1000) As Date
Public FTime(1000) As Date


FDate(t) = CDate(Mid(FindData("sm_Sys_BatchOpenTime"), 1, 10))

For H1 = 1 To n
FDateS = FDate(H1)
For r =1 to 50
FDateS = CDate(FDateS) + CDate(FTime(r)-Ftime(r-1))
Next
Next

Originally Posted by foxguy

Cummins;
I'm guessing that the values in FTime(r) and Ftime(r-1) differ by less than 1 (24 hours). When you add a value less than 1 it won't add a day onto FDateS.

The FTime delta is less than 24 hours but after adding all of the deltas (r) together it rolls through 24:00. The data actually displays as follows (There is more but I don't want to bore you):

9/16/2010 23:00
9/16/2010 23:30
9/16/2010 0:00
9/16/2010 0:30
9/16/2010 1:00
9/16/2010 1:30

Originally Posted by foxguy

Whoops, I misread your code.

Assuming that
r1 = 23:00
r2 = 23:30
r3 = 00

FTime(r3)-FTime(r2) = -23:30 (Negative), so it subtracts 23:30 instead of adding 0:30.

try CDate(FTime(r)-FTime(r-1)+iif(r<r-1,1,0))

I wasn't quite sure of how your code worked but, I used the following and it fixed it.
If FTime(r) > FTime(r - 1) Then
FDateS = FDateS + (FTime(r) - FTime(r - 1))
Else
FDateS = FDateS + (FTime(r) - FTime(r - 1)) + CDate(1)
End If