Lent starts on Ash Wednesday, lasts 40 days not counting Sundays and ends on Holy Saturday, the day before Easter.
In 2009, Ash Wednesday will fall on February 25 and Easter will fall on April 12.
February
Su Mo Tu We Th Fr Sa
...............25 26 27 28 = 4 days.
01 02 03 04 05 06 07 = 6 days, 10 days total.
08 09 10 11 12 13 14 = 6 days, 16 days total.
15 16 17 18 19 20 21 = 6 days, 22 days total.
22 23 24 25 26 27 28 = 6 days, 28 days total.
29 30 31 01 02 03 04 = 6 days, 34 days total.
05 06 07 08 09 10 11 = 6 days, 40 days total.
12 Easter
If you give something up for Lent then you do not have to give it up on Sundays.
But if you are giving up something constructive like sarcasm, then please keep it up even on Sundays and after Lent is over.