Symbolic dates?

[bluesqueak]

Is there a category for the discussion of certain dates as 
significant in themselves (ie things happen repeatedly on certain 
dates)? 

3385 (one of Rita's multi-posts) talks briefly about Halloween being 
significant; speculates Harry was conceived on that day. I recall a 
few other posts over the years which have also discussed Halloween, 
Christmas etc as significant symbolically.

Currently I've classed it as 1.5 symbolism - it doesn't seem to fit 
any of the subcategories for symbolism.

Pip