Megabirthdays started out in 1981 as the author began collecting celebrity birthdays from various sources in print and from radio and television shows. Back then they were collected on paper. The birthdays database was computerized in 1985 on an Atari 800XL computer where it then migrated to a Windows-based computer using QBASIC, then PowerBasic scripts to edit the database with. As of January 2018, the collection of celebrity birthdays has crossed the 66,200 mark.
Megabirthdays started out as the Demented Datebooks on a USENET group in 1995 as it featured daily doses of celebrity birthdays and some events on a day in history. In August of 1995, it began a presence on the World Wide Web on a website Interprep http://www.interprep.com/ which specialized in prep material for radio stations to subscribe to and use; and got a new name as Dave's Datebooks, which later moved to Dave's Fun Stuff in 1997 on a now-defunct free web hosting provider, then in 1998 to Dave's Fun Stuff http://www.davesfunstuff.com/ where it stayed until it moved to a now defunct Dave's Datebook website created in 2002 and lasted until 2006 when it moved to a subdomain of Dave's Fun Stuff as http://today.davesfunstuff.com that year. In 2015, it got its own url again, this time, as Megabirthdays located at http://www.megabirthdays.com/