First, before anything else is said, it has to be pointed out that that is a horrid sentence.
It seems to mean that they want the trial to be completed within 12 months.
It's nothing to do with the idiomatic greeting "Good day".
When one (of those people who live/die/kill for love) has a good/positive/enjoyable day, they naturally feel their outlook makes sense/is vindicated.
And that happens often, because such people tend to have lots of "good days".
It's also possible it's the article writer to whom live/die/kill for love seems like a sensible life-plan. The words themselves are ambiguous, but I'm swayed to the first interpretation because of the reference to such people having lots of good days.
Since presumably the writer isn't a "love extremist" herself, she wouldn't have the good days. And thus probably wouldn't think in terms of such an outlook [only] making sense on those days.
Best Answer
Excess deaths generally means over and above those that would have died anyway - the normal mortality rate for that population. The assumption being that those are the deaths you can blame on the war.