best time to go to El Rastro

Well, the time has arrived. I leave tomorrow for a week in Madrid then a month in Salamanca. I'm looking forward to the trip, and I was wondering about going to the Rastro while in Madrid - when is the best time to go there? Friday? Saturday? Sunday? And should I go early or late. Crowds aren't a big problem, I just don't want to get deluged.....

Thanks guys - a quick answer would be much appreciated.

If you want to see the Rastro market you have to go on Sunday. There is no market any other day except on other official holidays (15 a year). It's open from about 10 am to about 2.30 pm. It's probably less crowded first thing in the morning, but more fun as it gets closer to closing time when everybody starts heading for the bars. Any other day of the week it's nice to stroll around the side streets where the permanent junk and antique shops are. You may overlook them on a busy Sunday.