Groundhog Daynoun [ C usually singular ]
uk/ˈɡraʊnd.hɒɡ ˌdeɪ//ˈɡraʊnd.hɑːɡ ˌdeɪ/in the US, 2 February, which, according to an old story, is the day the groundhog wakes up after sleeping through the winter. If it sees its shadow on this day, there will be six more weeks of winter, and if it does not, spring will start early.
a situation in which events that have happened before happen again, in what seems to be exactly the same way:
Once again, we had an agreement, we all shook hands, and once again they come back and say no. I guess this is Groundhog Day.