It’s healthy to have an end date set.
For your: program, goal, project, experiment …
If you don’t know when it’s going to end, why are you starting in the first place?
In addition, an end date forces you to either accomplish what you set out to, or not.
If you enjoy beginning things without ending them, I guess that’s fine …
… if it doesn’t bother you.
Personally, I like completion.
Now, completion doesn’t necessarily mean ‘an end to the entire journey’.
There can be stages, sub-goals, and milestones.
But there must be a deadline set for something, to ensure progress.