begin by looking for somthink like This:
in the current class (the one which hold the UI)
DDX_Control(pDX, IDC_TIME_ACTIVEX, TIME_VAR);
: is the name of the control on the UI.
: is the variable Name.
Then look for the TIME_VAR
Calls you mau find one or more statements by which you display the time is some format.
Too, you may find something like :
if you find such statement you may look ine the formula passed to that function