Student or Learner
Is the future (continuous) tense in the 'until' clause correct?
He has to live with his parents until he will leave/ will be leaving school for college.
My reason for the tense comes from Martin Hewings's ADVANCED GRAMMAR IN USE (2005 edition): It is still a few months until he will be leaving for college.
Could I ask native English teachers to help me with this question? Thank you very much.