You have to count from the day you landed as a PR, your first 5 year period as a PR. During that time, you can not have been outside Canada more than 1095 days. After you have been PR for 5 years or more, it's always the previous 5 years they look at.
It takes 67 days to get a PR card renewed, see
http://www.cic.gc.ca/english/information/times/canada/process-in.asp#pr_card Before you get your PR card, you are still in status in Canada. You can use your landing papers to prove your status but if you are already moving back in May, you will have taken care of registration, drivers license, health care and everything else long before you apply to renew your PR card so you will not need it.