I try not to put a time limit on my long-term goals. Mostly because I often am unsure of how reasonable they are.
I will, however, use a schedule for my short-term goals. I mean, if you wanna gain 30kg of muscle, you first have to gain 10kg. Your experience in gaining the first 10kg will provide a better window of how much time it’ll take you to gain the next 10kg.
In the macro-sense though, if you wanted to compete as a 90kg bodybuilder and needed to gain 32kg of muscle, this would probably take you in itself almost a year and a half (averaging about 2kg/month, which is a little on the high side, but possible, even if natural. I’m basing this not on experience, but on several things I’ve read, so take it with a pillar of salt). Then you’d probably need to shed about 30 kg of fat (just feels like a good number- you’ve got some fat on you currently, and you’ll add more on your bulk), which will in and of itself probably take you half to a full year in and of itself (average of 2kg/month, give or take some).
So more realistically for that goal, you’re looking at two and a half years.