As we all know a Permanent Resident is required to physically present for 1460 days but at the same time law says "You must also have been physically present in Canada as a permanent resident for 183 days in each of four calendar years that are fully or partially within the six years immediately before the date of your application".
Now the question is If a permanent resident is going to complete 1460 days in April 2016, can he apply in April or he has to wait till June 2016 to complete 183 days requirement for a calendar year.
Does not matter how many days you are present in the year you apply for citizenship. 183 days is any of those four years with in last six years.
if you qualify in april 2016, you can still apply if you are present in canada for 183 days minimum in the years 2015, 2014. 2013. 2012..