Criteria in what I think is order of importance
- Was it released at Christmas? Die Hard, no.
- Is it played on TV year after year at Christmas time? DH, yes (but would it have been if not for 3 & 4?)
- Is it set near or over Christmas? DH yes
- Is Christmas important to the plot? DH Yes
If the vagaries of broadcasting whim make something a Christmas movie by playing it every year over Christmas, does it cease being a Christmas movie when they shelve it for newer films? How many years scheduling converts a non-Christmas movie into a Christmas movie? This is why I think mere screening time is a poor criteria.


