I dropped a letter off on a Tuesday for my dd and the school was notified(by the county not me) by Friday.We got the response letter on Saturday.
For my son I dropped a letter off on a Friday and the school was notified by Tuesday. Pretty quicky response time around here if you fill out the form correctly.
Technically here you need to keep the child in school till you get the response letter,but if you get that reply before 5 days missed you avoid truancy.Here they have 2 weeks to reply to a home school notification.Ofcourse it does help a wee bit if you know the truancy officer and he also happens to be the person who handles the home school notification forms

No way was I going to send my ds back to be bullied while I waited for a response.My dd could have gone,but it was easier to just keep her home and get into the home school mode.