I think eBay thinks every day is a business day. I left feedback for a seller last night and that stupid question about whether my item arrived inside the estimate asked if my item arrived before Sunday 15th November. Sundays shouldn't come into it as far as I'm concerned.

I panic when there is a long weekend that isn't observed in every state. Buyer buys and pays on Friday night, you don't post until Tuesday, buyer gets upset because it took 4 days for you to post it, when in actual fact it was only 1 business day. I now send buyers a message on long weekends that aren't nationwide "Due to the long weekend in NSW this weekend, I am unable to post your item until Tuesday". Given my handling time is 5 days, I shouldn't have to do that.

If you think this could be an issue for you next year, I'd be extending your handling time. Most buyers don't give 2 hoots about premium badges and whatnot. If nothing else, it gives you a bit of breathing space and reduces the stress levels a bit. You can still post same or next day, but if covers you for normal weekends and long weekends that as far as eBay is concerned, are normal business days (in my opinion).