jellybeannn -4 Junior Poster

I'm creating a cash flow calculator,
start and end date is entered, and then dates according to months in between are displayed.
If the month is Dec or Jan t1 should change accordingly,

if (validation.Month == 12)
            t1 = t1 - 14;
if (validation.Month == 01)
            t1 = t1 - 28;

after this has happened remaining dates should be t1 = t1 - 28
Can anyone please show me how to do this?