Yesterday I placed my direct ancestors' birthdays onto a Google calendar. I did this so I could use the information to plan 'birthday' posts, but it had an interesting side-effect.
Seeing the birthdays plotted out visually in this way made me notice 'birthday clumps', where ancestor's birthdays are clumped close together. I had noticed this coincidence with my parents' and my childrens' birthdays, but it was incredible to see it across the generations (btw, I only went back about 5 generations, where I'm certain that what I have is birthdates & not just baptism dates). Some ancestors' birthdays are so close that they are on the same day as their grandparent's.
Does anybody else have 'birthday clumps'?