The duration of Knock First is 1800.0 seconds.
The duration of Dr. Knock is 1.63 hours.
The duration of Don't Knock the Twist is 1.48 hours.
The duration of Knock on Any Door is 1.67 hours.
The duration of Don't Bother to Knock is 1.27 hours.
The duration of Don't Knock the Rock is 1.42 hours.
First Round Knock Out was created in 1987.
Knock First ended on 2004-10-01.
Knock First was created on 2003-10-06.
The first occurrence of the multiple repeated knocks appears in Series 1 Episode 10 - The Loobenfeld Decay:Sheldon: (Knock, knock, knock, knock) Leonard, (Knock, knock, knock, knock) Leonard, (Knock, knock, knock, knock) Leonard...Sheldon: (Knock, knock, knock, knock) Penny, (Knock, knock, knock, knock) Penny, (Knock, knock, knock, knock)Penny, (door opens) Good morning.
knock knock Who's there? Yes, it was indeed Shakespear that invented the knock knock joke, first using the format in one of his plays. Possibly, anyway.
Don't open the door unless you knock first.
The duration of Your Safety First is 2580.0 seconds.