Until

 1. The sun doesn’t rise until after dawn.

(dawn = the time just before the sun comes up; the light that appears before the sun rises)

 2. It’s still light outside until dusk.

(dusk = the time after the sun goes down; the light in the sky before the darkness, before the moon and the stars come out.)

 3. He can’t wait until winter.

(can’t wait: to look foward to something; to be happy about a future event)

 4. They can’t wait until summer.

 5. She won’t leave work today until 6:30 p.m.

 9. He usually waits until he gets to work to have a cup of coffee.

(In this sentence, "until" is used as a conjunction joining two clauses.)