I think you cant tell like "how many days you spend?" but you can ask "how many total hours you spent?" its because you can start your new track today, make some patterns and drumloops, then you save it and goes back to your older projects, then after week you come back to this project etc etc. Thats why you can finish several of your older projects in one week or so. And it depends on genre, edm music is more complex than hip hop because of drop, break, verse etc. But most of hip hop is "verse, hook, verse, hook, hook". And 2nd verse is the same is 1st verse
So DJ Mustard beats is very simple, he told in interview that sometimes he made 10 beats a day. But Timbaland beats is more complex, sometimes there is live ethnic percussion so it takes some time to record it, sample it, and make some loops with these sounds. But i dont think that complex tracks and many many sounds is good. If i want to dance to DJ Mustard tracks (1 bass, 1 lead, 1 drumloop) then i think its good, even if i dont understand english and dont know what lyrics)) For me sometimes its boring to make some simple beats and i am making more complex, but there is a chance that i never finish this track cuz i dont want to make that anymore and prefer to make some newer tracks)
Also it depends on how many hours a day you spend on music. If you dont have dayjob and your job is making music then its faster than if you spend on music 1-2 hours a day.