SUM(c_TimeTotal) will return the value of c_TImeTotal not a sum. It's the same thing as saying Sum ( 5) --which equals 5.
Sum ( TODO::c_TimeTotal) will sum the related TODO records, if defined in Paycheck--but this ignores any portal filtering as this evaluates at the data level, not the layout level.
You can get a portal total that reflects the portal filtering if you use this method:
Define a summary field, sTotalTime in TODO and set it to compute the total fo c_TimeTotal.
Place a second portal to TODO on your layout. Give it exactly the same portal filter, but specify that it be only one row in size.
Put TODO::STotalTime inside this filtered one row portal. (You can make the portal borders invisible to make this look like any other field on your layout.
Oh so silly ! ... best to walk away and come back. I had done it right, just haven't dealt with time formatting much .
4:30pm [ 12 hr format ] does not intuitivey come to mind as 16:30 hrs