here’s what i have always done:
if the dates are > 3 weeks out, i am informing. i wont be in. i inform. then i don’t show.
if the dates are < 3 weeks snd only say a long weekend: again, i inform.
if the dates are “tomorrow”: i inform.
that’s all there is to it. if your “policy” is “find coverage” never do that part. managers can manage.