Jump releases in Japan on Mondays, but scans come from a source that leaks it early. The recent schedule has been:

Monday, April 16: (582) We saw this chapter on Wednesday, April 11
Monday, April 23: (583) Double Issue. We saw this chapter on Wednesday, April 18
Monday, April 30: No chapter
Monday, May 07: (584) We saw this chapter very early on Sunday, April 29
Monday, May 14: (585) We will probably see this chapter on Wednesday, May 09
Monday, May 21: (586) We will probably see this chapter on Wednesday, May 16

And so on.