
According to what I see here, Thursday
nights are Franconi's Pizza night.
The Big Bang Theory Season 4, Episode 21

Yes, but we all agreed
the third Thursday of every month...
The Big Bang Theory Season 2, Episode 20

It's Thursday.
The Big Bang Theory Season 2, Episode 3

or the third Thursday
in a month with five Thursdays,
The Big Bang Theory Season 5, Episode 12

We don't have Thai food on Thursday.
We have pizza on Thursday.
The Big Bang Theory Season 2, Episode 20