I switched to Dvorak in a weekend (~8 hours) using something like https://learn.dvorak.nl/

It took me about a month to get comfortable and stop making mistakes and I switched back and forth regularly for the first two years (working in IT).

Now I mostly use Dvorak and when I switch it's not a problem but my typing speed in Qwerty is about a third slower.

Having done it, I'm happy with it but I probably would have learned Colemak instead because it's closer to Qwerty and would make those infrequent switches easier.