“Batman Day”

This year "Batman Day", the annual event organized by DC Entertainment to honor costumed crime-fighter 'Batman', created by Bob Kane and Bill Finger, falls on September 21, 2024:

"...the first 'Batman Day' was July 23, 2014. This was the year of the 75th anniversary of the first appearance of 'Batman' in 'Detective Comics' in 1939.

"The day was chosen to coincide with San Diego Comic-Con. Subsequent 'Batman Days' have been on the third Saturday in September..."

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