"S-H-I-T" joke

A businessman got on an elevator in a building. When he entered the elevator, there was a blonde already inside and she greeted him by reciting the letters,
"T-G-I-F."
He smiled at her and replied, "S-H-I-T." She looked at him, puzzled, and said "T-G-I-F" again.
He acknowledged her remark again by answering, "S-H-I-T."
The blonde was trying to be friendly, so she smiled her biggest smile and said, as sweetly as possible, "T-G-I-F" another time.
The man smiled back to her and once again replied with a quizzical expression, "S-H-I-T."
The blonde finally decided to explain things, and this time she said, "T-G-I-F, Thank Goodness It's Friday, get it?"
The man answered, "S-H-I-T: Sorry Honey, It's Thursday."
More Blonde Q & A
Why do blondes wash their hair in the kitchen?
That's the proper place to wash vegetables.
What is a Blondes favorite nursary rhyme?
Hump me dump me
What do you do if a blond throws a grenade at you?
Pull the pin and throw it back.