He wants me to change the days I go into the office! 
I went in to see him months ago and discussed my return to work with him. I decided I wanted to go from 4 days a week to 3 and to work from 10 - 5 instead of 10 - 6. He said could I do Mon, Wed, Thurs and I explained that I really wanted 3 consecutive days. Either Mon, Tues, Wed, or Tues, Wed, Thurs. Explained my reasons and he agreed I could do Tues,Wed, Thurs.
I asked him to put it in writing and he agreed.
I have since chased him for this email twice. he finally came back yestrday and said he felt strongly that I work on Mondays as all staff are in on that day. I go back next week!
I have emailed him and said my childcare arrangments have been sorted now, and that if everyone is in office on Monday isn't it better that I'm not in that day as there is a lot of cover in office, and we all work on our own projects anyway.
Think I've worded the letter really well, hope I have, I await his response.