Saturday is Groundhog Day, but despite having their own day, it seems that groundhogs have been largely ignored by inventors. Groundhogs are referenced in the claims of only four patents, and mentioned in only 106 U.S. patents since 1976.

There is one prominent piece of technology associated with Groundhog Day, however, that should be very familiar to horopalettologists (look it up):

This iconic flip clock — the Panasonic RC-6025 clock radio — restarts every day for Phil Connors in the classic movie Groundhog Day. Split-flap flip clock displays (or the much easier to say “leaf-type digital displays”) were first patented in 1965:

U.S. Patent No. 3,220,174

While briefly popular, these displays were soon supplanted by LCD and then LED displays. They still have a small but dedicated following, however, and vintage flip clocks like the RC-6025 are now selling for hundreds of dollars on eBay: