You disappoint me, Zombie. There are plenty of valid reasons for the heroes to wait the year.

1. Luke had to wait the year to go to Dagobah to be at Yoda's deathbed. One can't hear someones dying words when they are alive and kicking now can they? Why would he go there with enough time to get the training he thought he needed? Turns out he didn't need the training after all (convenient, ain't it!)

2. Lando had to wait the year to get full time at Jabba's palace. Trust me, the dental plan alone is worth the wait.

3. Leia needed time to drop a few pounds and tone-up for when her attempt failed, she might be forced to wear an iron bikini.

4. Chewie. Two words: Flea dip.

I'm sure there were plenty of other valid things the heroes could be doing in that year.