
...or B, more than nine nights
in a three-week PERIOD, or C...
The Big Bang Theory Season 2, Episode 10

one day a week
for a trial PERIOD.
The Big Bang Theory Season 7, Episode 24

It was a classic western
set in the post-Jurassic PERIOD,
The Big Bang Theory Season 9, Episode 14

Well, he used a PERIOD
instead of a question mark,
The Big Bang Theory Season 9, Episode 16

Easy. 40 weeks from the date
of her last PERIOD.
The Big Bang Theory Season 11, Episode 16