Agreed.
He did pretty much the same for Easter.
In 1955 the only day off skilled workers (e.g., machine repairmen) at Detroit Transmission got off between New Years & Memorial Day was Easter. It was almost certainly a secular day for them.
Hi-jacked is hardly the correct term in any case. The Christians didn't hijack the Winter Solstice any more than the Romans hijacked the Greek myths and legends. It's just history.
Carrol