Meaning of “through” - Learner’s Dictionary

through

preposition uk us /θruː/
ONE SIDE TO ANOTHER

A2 from one end or side of something to the other:

The River Seine flows through Paris.
The sun was shining through the window.
She cut through the wire.
START TO END

B1 from the start to the end of something:

He worked through the night.
The phone rang halfway through the programme.
BECAUSE OF

B1 because of someone or something, or with someone's help:

I got the job through my mum's friend.
He became ill through eating undercooked meat.
UNTIL US (UK/US to)

from a particular time until and including another time:

The store is open Monday through Friday.
I worked there from May through September.

(Definition of “through preposition” from the Cambridge Learner’s Dictionary © Cambridge University Press)