Quantitative ASI: right after AGI is created because there's not much of a tangible barrier between subhuman, par-human, and superhuman task completion. Could be as soon as 2024 with "frozen superintelligence."

Qualitative ASI: probably mid 2030s. We'll probably need a lot of neurofeedback data to get to strong AGI and, then, true superintelligence.

Singularity: not going to lie, I have my doubts about a Kurzweilian Singularity. I think the effects of ASI will resemble it for a while, so again, 2030s into 2040s.

Edit: Should probably stress that quantitative ASI is better described as "superhuman general task automation." We already have superhuman AI, in very narrow fields like chess, go, and arithmetic. You can consider these narrow task automation programs since the "AI" moniker is tenuous to begin with.