If I made a submission on 7th of May, does this mean I have 2 submissions left until 11th of May, since I made my first submission in the last 7 days of the contest?
Or maybe the 7 day period was reset at the end of 7th May and now I have 3 submissions left? Or do the weekly 3 submissions add up from the beginning of the contest? Thank you for the clarification.
Please see this previous question for an explanation of how our submission limits work in general. (That answer was for a different competition with a 6 submission per 14 day limit.)
Because your submission on May 7 is within all 7-day rolling windows leading up to the close of the challenge, it will count towards your limit until the challenge is over.