What happened on May 4 ?

International Firefighters' Day.

The Netherlands - Remembrance of the Dead.

People's Republic of China - Youth Day (???, commemorating May Fourth Movement).

Republic of China - Literary Day (???, commemorating May Fourth Movement).

Star Wars day, "May the 4th be with you" pun on "May the force be with you"

Saint Judas Cyriacus

Saint Ladislaus of Gielnow

Saint Florian

Saint Godehard

Saint Malou

Saint Ethelred

Saint Silvianus

Saint Titianus

Saint Willerik

Saint John Houghton, Saint Robert Lawrence, Saint Augustine Webster, Saint Richard Reynolds, and Saint John Hale; all put to death in 1535.

Saint Monica of Hippo (d. 387)

Blessed Catherine of Park