Happy Birthday Tchaikovsky

Tchaikovsky was indeed born on May 7th, in 1840. On that date, the young Johannes Brahms was celebrating his SEVENTH birthday, having been born on May the seventh in the year 1833. Not a totally unusual coincidence: the eminent Hungarian composer Zoltan Kodaly was born on December 16th, 1882, a date usually given as the birthdate of Beethoven, 1770. (I say "usually" because his date of baptism is December 17th, and a window of 24 hours is assumed.)