When you wish someone to have a good weekend, you say, "Have a good weekend!". But what about wishing someone to have good holidays? Does "have good holidays" sound weird? I'm just asking because I have never heard it before. I have only heard "Happy holidays!".
You can use "Happy holidays!" or "Have a good holiday." instead of "Have good holidays." because "Have good holidays" sound weird and very rarely used. Actually I didn't hear it from someone since I born :).
(language is living and changing) If you start saying it maybe be others will say it and it will become used. lot of used habits sound weird! we say „morning“ and mean „good morning“ but but actually we want to say: I wish you (might/will) have a good morning.
It seems to me that it is better to say not "Have good holidays!", but "Have a good holiday!". This form is much more natural and common.