I am transcribing a children's television show where the kids are
learning beginning French phrases; i.e. 'hello', 'my name is', etc. 
All of those are easily researched, but I don't speak French, and this
one is causing me problems:

The host asks, "How would you say 'time to go to school'?"
The teacher replies, "You mean, 'school is coming back'?"
The host replies in the affirmative, and the teacher says something
that sounds like:

"say la hauntray" (completely phonetical)

The closest thing the French speakers I know have come up with is
along the lines of "C'est l'entere" (time to enter?), but I'm not sure
that really fits.

Looking at the phonetical, and the context of the conversation, what
would be the correct French phrase here?  What is it's actual
translation, and any colloquial meaning, if any.

The phrase you want is "C'est la rentrée." Literally, "It's the
re-entry." "La rentrée" is the French term for the beginning of the
school year (or semester).

"La rentrée = the back to school/work period at the beginning of
September (and also in January, etc.)"

Word Reference Language Forums
http://forum.wordreference.com/showthread.php?t=47740

"It's back to school (c'est la rentrée)!" 

CBC: C'est la Vie
http://www.cbc.ca/cestlavie/words/words_r.html

My Google search strategy:

Google Web Search: "c'est la rentrée" "back to school"
://www.google.com/search?hl=en&q=%22c%27est+la+rentr%C3%A9e%22+%22back+to+school%22

I hope this helps! If anything is unclear or incomplete, please
request clarification; I'll be glad to offer further assistance before
you rate my answer.

Best regards,
pinkfreud

Lightning fast, with an excellent answer to boot.  Thank you, thank you!

Thank you very much for the five stars and the nice tip!

~pinkfreud