With holidays, do I use the article? Do certain days use the article, while others don't?
www.germanveryeasy.com/zu

On this page, the examples below were used:

zum Muttertag

zu Silvester

zu Ostern

zu Halloween

Why don't "Silvester", "Ostern", and "Halloween" use the article? And, a bit inverted now, but, why does Mother's Day have it and the others don't?

Question

With holidays, do I use the article?  Do certain days use the article, while others don't?
www.germanveryeasy.com/zu

On this page, the examples below were used:

zum Muttertag

zu Silvester

zu Ostern

zu Halloween

Why don't "Silvester", "Ostern", and "Halloween" use the article?  And, a bit inverted now, but, why does Mother's Day have it and the others don't?

Answer

Off the top of my head, I'd say that the ones that explicitly have "Tag" or a specific date in them need the article:
– zu Neujahr – zum Neujahrstag
– zum Maifeiertag / 1. Mai / Tag der Arbeit