Hey there,
i like to know, if it’s possible to connect tasks so if i change/move the date of one task, the other one (the connected task) moves similar to the first one.
Example:
Task A is fixed on 28th September, Task B should be done 2 weeks before (14th)!
My Boss asks me to change Task A to 21st September.
Is it possible to connect Task B so it automatically gets the 7th September as the new date??
(to keep the time dependence!!)
Regards
No this is not yet possible 
Actually, I think you can!
From another reply of mine, with minor changes:
Move tasks relatively in Timeline view; they don’t need to be “connected.” Click+drag a box around the set of tasks you want to move to highlight them. Then just click+drag any one of them to move all of them. I couldn’t see this documented in the Guide in writing, but it’s in the video at 1:35 at Timeline View in Asana | Product Help Center • Asana Product Guide
Larry Berger
Asana2Go & Asana Certified Pro consultant at Trilogi Software
Thanks for the tip @lpb. That works if you don’t have too many tasks or they are close to each other in the Timeline, but that’s a great idea 
Good point about tasks not close to each other. I forgot to mention that in Timeline you can also do Cmd-Click (Control-Click) to multi-select by toggling individual tasks, which is particularly useful when they’re spread out.