Fathers and Parents

[Johnmeh]

Surely it's Fathers' day? Every card I have ever seen says Father's.

Is it a parent's evening or a parents' evening? Apologies if this has been done to death.

This drives me potty too. Father's and Parent's I think.

What the heck is the little mark called.

Apostrophe?

Fathers' Day because fathers (plural) are celebrated and Parents' Evening because all the parents of the children are invited - not one parent. The apostrophe goes after the s when the word is plural, and before the s when it is singular.
You might say "in my father's day..." or "his father's car is white" - referring to one father.

Mummy thank you, my mind just doesn't retain these things, I will try though.
did that will definitely not be retained

Well, we did Mother's / Mothers' Day recently, and usage seems to be with 's whatever pedants might say. www.mumsnet.com/Talk/pedants_corner/2586000-mother-s-day-or-mothers-day