Why do some active players have a rating in the March supplement and others (also active) do not? I had two rated tournaments for February (on the 9th and 16th) and yet I don’t have a rating in the March supplement. It just shows February 09 for my most recent rating. I clicked on various other players and it seems mixed… some do have a March 2009 rating but many others do not. Is it because the supplement calculations are run earlier than the 9th of each month?
For this month and your case, yes. Rating lists are generated on the first Friday of the preceding month. Below is a link to a previous Mike Nolan post on the topic.
http://main.uschess.org/forums/viewtopic.php?f=23&t=5161&p=72010&hilit=rating+generated#p72010