Yes, for "human" languages, it is probably more than 90 days. More like a year or two. (Learning a second language well can easily take 6-7 years.) I meant 90 d

Yes, for "human" languages, it is probably more than 90 days. More like a year or two. (Learning a second language well can easily take 6-7 years.) I meant 90 days for programming languages. In my experience with foreign languages, first you struggle for a while and one day it unexpectedly "kicks in", suddenly you're able to comfortably use the language albeit not perfectly yet while the week before you was struggling to form simpler non-trivial sentences. Depending on your experience with foreign languages and the time you spend on learning the language, this can take from half a year to several years.