To apply for Canadian citizenship, permanent residents now both have to have lived in Canada for four years out of the last six, and also have to have lived in Canada for 183 days or more per year in four out of the last six years.
Previously, permanent residents only had to live in Canada for three out of the four years prior to their application.
As well, much to the chagrin of international students and foreign workers, the time spent in Canada prior to obtaining permanent residency will no longer count toward the residency requirement.