Early bird...? ...or?

There are people who suggest that if you want to get more done, you should simply leave bed an hour earlier - in that way, you would worst case get 365 additional hours a year.
However, I am convinced that it is not a universal - for early birds is certainly excellent, for they can just go an hour earlier to bed at night, at which time they are not as effective. But for the night owls, I doubt that there will be any outcome - except perhaps the negative one that they will get one less hour of productive time at the end of the day.
So although I'm an early bird (at least in the morning), I am not blind to the fact that the advice is given by early birds to early birds without taking night owl habits much into account.
If I were to give the advice, I think that I would state it as

Expand your productive time by one waking hour instead of sleeping. 

Early birds can get up even earlier, Night owls go to bed later, and either can where necessary gain back the sleep on the time of day, where they are less productive.
But in any case it's a bad idea to unconditionally accept advice that lumps all recipients together in one barrel.
(Translated from Tidligt op og...? eller?, originally published March 30th, 2017)