eBay buyers change the days of the week in which the do most of their purchasing about each year.  I have been selling on eBay for over 4 years and have seen the buyers' heavy shopping days change quite a few times over the years.

When I first started selling on eBay, Wednesday Thursday, Friday, Saturday were the heavy buying days. 

Now it seems that the heavy buying days are only on Wednesday and Thursday with little buying activuity on Saturday. 

Sundays, Mondays & Fridays are especially slow. 

No one buys from me on Mondays or Fridays especially.  I guess the first day of the week gives people the blues and the hectic rat race on Fridays keep them preoccupied and tired after a week's work. 

Saturdays people are probably outdoors enjoying the sunny weather.  What's wierd is that they used to buy heavily on summer Saturdays a few years ago. Why?  I do not know.

If you're an eBay seller, you might try starting your actions on Wednesday, Thursday and Saturday afternoons.  Try avoiding putting items on auction on Monday, Tuesday, Friday and Sunday. See how it works.  I sell movies and books, so perhaps this is just a behavior pattern of that particular audience. 

But if you notice certain days getting very little bidding activity, cease all auction listings on those days. 

Unsold auctions can really stack up your eBay fees if you have a lot of items listed on eBay.  I have 5,000 items on eBay and it is important not to get a lot of unsold items fees on Mondays, Tuesdays, Fridays and Sundays.

Be extra alert to your buyers' heavy shopping days.  eBay buyers are like birds on a wire - they all fly away at the same time and they all land at the same time.  Be wise and shrewd with the days you list your items!