Ratings are always calculated on the most recent ratings. Official ratings are used for pairing purposes, tournaments must have a lead time to publish ads and draw entrants. People need to know which class they are in! So, if published ratings of you and your opponent are both say 1700 and when the event is rated they are 1600 and 1800, the latter two ratings determine the rating changes. So, ratings do update immediately, just not the official ones.
Sometimes if a rating report is submitted late, the USCF will re-rate your last few events.
when I was new to USCF chess, it took a few months to get events rated, it was all done manually! Now, you play one day, it's rated by the next.
Hello, I have noticed and heard that the ratings for the USCF are chosen on the 3rd Friday of every month and then they become official in the next month. I was wondering if the rating that my opponent officially has is the one that will influence my rating, or if it is his unofficial rating that exists but is not official until next month.
And also, a less important follow up question of mine is how come they have this system, why do ratings not update right when TDs insert game results, why wait so long. I am farely confident that there is a logical explanation. I appreciate the help.