Article D3142-77 of the French Labour Code
In the absence of the agreement mentioned inarticle L. 3142-129, the employee informs the employer by any means giving a date certain, at least three months before the start of the leave or the period of part-time work devoted to teaching or research, of his wish to benefit from this leave or a reduction in his working time. The employee shall specify the duration of the leave or the extent…