Seniors

But as a rule of thumb, around 4 hours before turning in.

Naturally, it would be less for someone young and/or with high metabolism - and an athlete would be able to disregard that time limit entirely.

But in general - especially among the elderly and/or people who should lose a few, 4 hours is best.

I recommend making a thermos full of your favorite tea (no sugar), and you do get used to it - as hard as it is at first.

As you said: Easier said than done.