Honestly, it’s quite possible (and incredible, when you think about it) that the entirety of the first Star Wars takes place over the course of just three days.
Day 1: Vader captures Leia and her ship, 3PO and R2 land on Tatooine with the plans, get captured by the Jawas that evening.
Day 2: Owen buys 3PO and R2, we’re introduced to Luke, watch him clean the droids, see the Leia hologram, Binary Sunset, etc. Ends with R2 running away.
Day 3: Luke searches for R2 first thing in the morning with 3PO, gets attacked by sand people and meets Obi-Wan. Goes to Obi-Wan’s hut, learns about the force, gets lied to about his father. Owen and Beru get killed, Luke finds out, goes to Mos Eisley with Obi-Wan. They meet Han and Chewie, set course for Alderaan.
We know for certain THAT much took place over three days at least. The question is how long it takes them to get to the Death Star by hyperspace. It certainly feels to the viewer–or at least it always did to me–like they arrive at the Death Star on the same day Alderaan gets blown up which was the same day they took off. And the state the place is in when they get there seems to support that. Obi-Wan “feels” the disturbance in the force at the time it happens too.
Anyway, they get to the Death Star, rescue Leia and Ben dies - that clearly all happens on the same day, and then you would think since the Death Star is about to destroy the rebel base and there is no time to evacuate apparently that time is of the essence. So it seems like the whole battle takes place later that same day, or it always felt that way to me. Though again, because they get to Yavin via hyperspace we aren’t 100% sure how long it took them to get there.
At any rate, it does make it seem a bit strange that Luke got such an emotional attachment to Obi-Wan after only truly knowing him for a few days and only thinking of him as a bizarre old hermit before then.
This was hotly debated in the WEG RPG. The first edition had the travel time from Tatooine to Alderaan in days. They revised it to hours.
But, one reason that Luke is so sad to lose Ben (and this is pointed out in the film) is that Ben knew his father and Luke is hungry to learn about his father. His uncle never talked much about him, but Ben seemed to be willing to. So in Ben he finds this connection to his father and then loses him. That is a pretty good reason to be sad.
The travel time from Alderaan to Yavin doesn’t really matter. The Falcon and Death Star travel it in similar times with the Falcon arriving enough ahead that the rebels are able to analyze the data and find the weakness they needed and prepare to launch an attack. Considering that Rogue One has the secret mission leave from Yavin and Leia is attacked at Tatooine, It is not hard to imagine that all 3 planets are in the same area. But that really all depends on how far a ship can travel in hyperspace in an hour. If you can cross the galaxy in a day, then the planets can be quite far apart, but would still be the same general area (same quadrant).
In TESB the issue is different. The Falcon’s hyperdrive is out and they have to take the long way. That changes any trip from hours or days into weeks at the least. And that is just to get to a neighboring system. From a storytelling perspective, the time is irrelevant. It is enough time for you to believe that Han and Leia are in love and that Yoda has trained Luke to be a quasi-Jedi (the way I look at it is that Yoda trained him in the skills he needed, but Luke hadn’t passed the tests to confirm he had learned the most important lessons - that he came back from confronting Vader proved he had taken in Yoda’s training). It really is however long you as the viewer thinks it needs to be to accomplish those two things. For me, that is about 2-3 months. The story skips to the arrival at Bespin and Luke’s vision so how long it took is never addressed. I think with Lucas’ idea that 3 years happen between ANH and TESB and 1 year between TESB and ROTJ that a longer time for the events in TESB fits better, but that is me.