april fools' day

Baptism day 1961.

How did the unofficial title come about?

“…[one theory suggests] that April 1 trickery stems from switching to the Gregorian calendar. One such explanation dates to 1564, the year French King Charles IX (1550-1574, died young) moved to standardize January 1 as the start of the new year, which had often been celebrated on Christmas, Easter, or during Holy Week (the seven days before Easter).

“Despite the royal edict, some French people kept with the Holy Week tradition and celebrated the new year in late March to early April, becoming the first ‘April fools.’”

​interestingfacts.com