Anyone on maternity leave is also required to give notice of when they intend to return and if you haven't been told prior to the 31st dec date on your contract they can't really make you stay longer if you were to find work for January. You would be expected to be there until December as you are now out if the notice period to get a job for September. You need to speak to the school if you are looking for September jobs and see if they have any incline of an earlier return. In't first ever job was maternity from sep til Easter and I did have to pester nearer the time and did let them know that unless my contract was extended then I I would be looking and applying for the summer term. Turned out my post holder was then signed off sick to the summer and I was given a new contract til 31st August then I was actually made permanent due to other staff leaving and parents of my class recommending I was kept on! Hope someone can give you at more definite answer though.