Microsoft sometimes shocks you, it is like they do not follow the rules that Google and Yahoo! set forth in being secretive about how, why, what and when they do search index updates. Yahoo! recently began giving us updates, that yes, we did do an update. Google followed suit, to let us know during an update, what to expect, in order for us to give feedback on the update. Today, I noticed a post in a WebmasterWorld thread where MSNdude says, and I quote;
It's a pretty safe bet that we won't do an update on a Sunday afternoon -- especially not one as beautiful as today was. :-) Saturday is out too. In fact, we're unlikely to do an update on a Friday, since it can mean sacrificing our weekends if there are problems.
Now, I try my best not to update our sites on Fridays, Saturdays or Sundays also. But I never saw Google or Yahoo! say they would most likely not conduct a search index update on any particular day. In fact, I think they have done index updates on the weekends.
Anyway, this is a good piece of information to know about MSN. They most likely will not update the index on the weekends, or even on Fridays.
Forum discussion at WebmasterWorld.