To wonder why we say 'at chrismas'?

[Thisusernameistakenagain]

"What are you doing at xmas?'

"Are you having family over at xmas?"

We don't say "what are you doing at Saturday?"

Or even;

"What are you doing at new year's eve?"

"Are you going out at new years eve?"

We say ON Saturday. ON New Year's eve.

We don't say 'On Christmas.

It sounds wrong doesn't it?

Why is it like this?

Educate me.

I don't think I would say at Christmas. I would say 'what are you doing for Christmas?'. So that's another one to throw into the mix!

Because it's more than one day. We say at the weekend rather than on the weekend. Christmas is similarly a period of days not one day. If you meant the 25th specifically you would say on Christmas Day, not at Christmas Day.

I would say for Christmas and on New Year's Eve.

Some people do say ‘on Christmas’ (Darlene Love, for example). But it’s horrible and clunky and wrong.

We don’t say ‘at Saturday’, but then again, we don’t say ‘at Christmas Day’.

‘At’ seems to be used for the whole event; ‘on’ for a specific day.

I always thought it was more of a shortening of at Christmas time. So the whole season rather than one day.

Americans tend to say on Christmas and I find that sounds very odd.

I think people say at Christmas because it's a time period rather than a day. I would include Christmas Eve and boxing day in "at Christmas." I say for New Year's, for Thanksgiving, etc., because those are just one day.

@Angel2702

I always thought it was more of a shortening of at Christmas time. So the whole season rather than one day.

Americans tend to say on Christmas and I find that sounds very odd.

This. It's short for "at Christmas time". You say "on Christmas Day" like you'd say "on your birthday" or "on New Year's Eve".

’Christmas’ means the general festive period and and this warrants an ‘at’.

‘Saturday’ and ‘Christmas Day’ are singular and use an ‘on’.

Lower MC and WC use ‘on’ for ‘the weekend’ and ‘Christmas’ erroneously, and some celebrities like to use it to dumb themselves down.

Because the full sentence should be 'what are you doing at Christmas time'. The xmas festival is more than 1 day it is 12 days of Xmas, or 5 days of yule, bit Christmas is not only one day as a festival.
Its a bit like what are you doing at lunch time.
You wouldn't say what are you doing on lunchtime.
And again you wouldn't say what are you doing on the evening, you would say what are you doing in the evening, as either 'what are you doing on the evening, or what are you doing at the evening is not correct. It could be correct as 'what are you doing on the evening of the 24th' and then you could use on.

It used to be Christmas tide.

I think 'at Christmas' is short for 'at Christmas time'

I would say what are you doing for Christmas?

"On Christmas" makes my teeth itch. It's Christmas Eve/Day/Boxing Day.
"At Christmas" covers the whole period, so for eg if I ask someone what they are doing at Christmas I would expect something like (In normal years!): "Going to my mums Christmas Eve, then spending the day at home, going to in-laws in the evening and then to my mums again on Boxing Day to see my brother and his family".