I am due back in the office on 13th December when DS2 will be nearly 9 months old but have recently started feeling that this is too soon and that I may want to take another month or two. I have verbally agreed the return date with my employer but they have yet to send a formal letter although it has been confirmed over email. If I wanted to, could I now change the date to later, e.g. Jan 2011 despite there now being less than 8 weeks until 13th Dec when I am due to return?