Your mother's being impossible. Dollars to donuts you show up "whatever time you can" and you'll be raked over the coals for it being her least-preferred time. Doesn't matter what time it actually is; the point is her Christmas wish, which is that she gets an opportunity to emotionally abuse you.

My own mother is this way. I pretty much don't contact her any more. When I do, I never escalate; I grey-rock her. She caught on a few years ago and has tried to make me feel guilty about grey-rocking her, and she succeeded; it's a terrible way to treat anyone, and I have to keep reminding myself that she earned that treatment through her decades of terrible behavior.