All Fool's Day

All Fool's Day is a holiday.

Background
The event is celebrated on April 1, listed on the Pip-Boy 2000 screen.

Appearances
All Fool's Day is mentioned in Fallout, Fallout 2, and Fallout Tactics.

Behind the scenes
In the March 30, 2023 edition of Inside the Vault entitled "MODUS Broadcast," part of the post is written in binary. When translated, "01000001 01110000 01110010 01101001 01101100 00100000 01000110 01101111 01101111 01101100 01110011" reads "April Fools."