If he fights Pacquiao, it'll be in July, because they both can fight in July. Pacquiao has reportedly even said Spence isn't that good and doesn't hit that hard. Refer to this article: https://sports.mb.com.ph/2019/03/18/pacquiao-take-on-spence-just-like-ledwaba/
I personally think Pacman is too old for this challenge and Spence will indeed "give him that retirement check" as he said at his post fight press conference. I actually don't even want this fight to happen, because the outcome is a forgone conclusion. But hey, maybe it's the fight Pacquiao need in order to understand it's time to retire. If it was a 10 yrs younger Pacquiao, it would be a good fight.