1. Bill Murray was bitten twice by a groundhog during the film shoot, according to the late director Harold Ramis
Back in 1992, Ramis told Premiere magazine, "To be bitten twice means [Murray] stuck around after being bitten once. He's very game." Ramis said Murray was bitten during the scene when his character lets the groundhog drive a truck.
2. Despite what it says in the script, the film was not shot in Punxsutawney, Pa.
...but rather in Woodstock, Ill., roughly 45 miles from where Murray grew up.
3. Just how long was Murray's character, Phil, trapped in Groundhog Day?
Ramis once said Phil was trapped in Groundhog Day for 10 years, even though the original plan was to have him trapped for 10,000 years. According to the website Wolf Gnards, which ran the numbers, Phil was actually trapped for eight years, eight months and 16 days.
4. Tom Hanks was originally supposed to play the lead
During a 2009 Q&A in Chicago, Ramis revealed his original casting choice. Ramis said Hanks later told him, “Audiences would have been sitting there waiting for me to become nice, because I always play nice. But Bill’s such a miserable S.O.B. on- and offscreen, you didn’t know what was going to happen.”
5. A family of groundhogs was raised for the film
The wrangler who grabs the groundhog to hoist at the ceremony reportedly had a background as an animal handler, and raised a groundhog family with six babies just for the production.