Most people use a telephone.
a gimp
Step 1: you call someone to do it for you
Call the place and ask
It's called getting your PhD.
passer-by
"Let's call it a day?" is said when someone suggests packing up working for the day and going home.
By finding a place where someone can hire them to work.
Planetarium
You should call your manager or supervisor. It is not your responsibility to cover for someone else. You could also call in someone else in the position to see if they wanted to come in.
If you have the power (i.e. being an owner or boss of a place) then yes.
A place where a working model of planets and other heavenly bodies are kept is called an observatory or a planetarium.
Someone is an indefinite pronoun, a word that takes the place of a noun for an unknown or unnamed person. Example: Someone will call you when your order comes in.