After a successful interview for a new position, I started looking for new childcare arrangements based off the location before accepting the post. Once I'd accepted, I completed pre-employment checks and my references were all returned promptly. These were then sent on to be signed off by the recruitment lead. I need to confirm my childcare arrangements before losing the space, and my current manager is pushing for my notice now she knows I'm leaving but I still haven't had my unconditional. How long is reasonable from all pre-employments checks being complete to being signed off and unconditional offer granted?