[Mogger]

It can be worthwhile to know about an enemies' culture, including holidays.

They certainly know about ours, and use it to their advantage when attacking us.

Should, for some reason we have to deal with them, wouldn't it be better to do so when they have let their guard down, partying?

Hopefully we never have to use this knowledge, but if push comes to shove better than not having it.

[caddie]

The Battle of Trenton, NJ, when the US Army under Washington attacked the hung-over Hessians on the day after Christmas.

Yes that comes to mind.