As a frequent buyer on eBay, I don't buy from people on holidays, EVER. I buy from active listings where I can ask the seller questions if needed and I can get my items sooner by buying and paying. If I want something, I want it now, I don't want to wait 2 weeks until the seller gets back from his holiday, then have to wait the time for it to arrive.

If there was a way to filter out sellers who are on holidays, that would be my default setting.