Yes it's for a full month, but can run from say 5th to 5th etc. You get four day blocks with two days off in between, but if you are called on the second or third day of standby, you have to work into your days off which knocks the rest of the roster. In your standby month, you only get two guaranteed days off that month that can't change, so forget any plans you want to make. I've worked every standby I've ever done. It's not airport standby, but as you know, you need to be at the crew room within two hours of the call.