An extra page a day for teachers (5)
I believe the answer is:
inset
I believe this clue is a double definition.
'an extra page' is the first definition.
(I've seen this before)
'a day for teachers' is the second definition.
(I've seen this before)
(Other definitions for inset that I've seen before include "Part of magazine" , "Not taking proper care" , "subsidiary diagram" , "Something placed into another using tines" , "Magazine feature" .)