On Christmas or at Christmas?
What's the difference between on Christmas and at Christmas? Are they interchangeable? If not, when do we use which preposition?

I visit my parents on/at Christmas.
We had a great time on/at Christmas.

Question

On Christmas or at Christmas?
What's the difference between on Christmas and at Christmas? Are they interchangeable? If not, when do we use which preposition?

I visit my parents on/at Christmas.
We had a great time on/at Christmas.

Answer

In the UK, we say 'at Christmas'. I believe the the US they may say 'on Christmas' but I'm not 100% certain. It means the same thing. 
Any US people out there who can say if I'm correct?

Answer

In my part of the US "on Christmas" means on Christmas Day itself. "At Christmas" can mean Christmas Day itself but often encompasses an indeterminate period of time around Christmas.