If the current distribution amount continues per month then distribution will be done within the next 15 months. Probably a little bit earlier.
However distribution has already changed so it is not impossible that it change again. Therefore I would say it is not predictable. Just follow the announcements from distribution to distribution. I think it even does not matter if the distributions end within one, two or three years.
Can you already know when will the byteball distributions end?
Unfortunately thats not correct. About 15 rounds were calculated with the old rules (0.1gb for each 1gb you hold, now it is 0.2 for each gb you hold) and way less linked bitcoins added each round. Of course nobody can tell you exactly how many rounds will follow. I calculated +50k linked bitcoins (in the end it was much more) each round before the last airdrop and I came to the result that 6 more airdrops will follow (calculation was done in the middle of may, so we have one airdrop less, means 5 more). I guess we will have at least 4 more drops (imho 5 rounds) and if Tony changes the rules that bitcoin holders get way less, maybe we see 6 more rounds.