1 {scene: Dagobah}
1 Yoda: Luke! You must complete the training.
2 Luke: I can’t keep the vision out of my head. They’re my friends. I’ve got to help them.
3 Luke: How much more training can there be anyway?
4 Yoda: See, let’s. Two days have you been here. So... about 10 more years.

So the gang split up after leaving Hoth.

Luke goes off to Dagobah, meets Yoda, and trains to become a Jedi for... some amount of time that isn't very clear.

Meanwhile, Han and Leia and Chewie do some shenanigans in an asteroid field with the Empire, which takes maybe a few hours, then they go to Bespin and meet Lando. They go to dinner and get captured by Darth Vader. Total time elapsed: perhaps two days. We never see any indication whatsoever of people sleeping or days passing, so it might even be the same day.

Luke gets a vision that his friends are in trouble and leaves his training to go save them. So... he's been training with Yoda for... maybe two days?

He must be a really fast learner.