JJBA part timespans

Phantom Blood: 9 years (less than 3 months not counting childhood events before time skip)

Battle Tendency: 4 months

Stardust Crusaders: 50 days

Diamond is Unbreakable: 3 months

Vento Aureo: 8 days

Stone Ocean: 5 months (not counting two universe resets)

Steel Ball Run: 4 months