You can go through the tutorial and know the language in two days. Seriously if you ever want a weekend project, try learning elm.
Even if you don't want to use it, but just to be exposed to the ideas.
You csn be writing productive code in a week. If anyone tell you Haskell (or Purescript) is less than months to be productive is not being honest about what production level productivity entails. You can learn the fundamentals in less time, but the prized significantly more complex abstractions makes ramping up significantly slower. And this is coming from someone who likes haskell and is enjoying learning the language.
As someone who has used a lot of languages over the years, I really do say spend a weekend trying it out. The language has great ideas and a great philosophy.
