For purposes of the PR residency obligation, dates of entry and dates of exit ordinarily both count.
I do not know, though, if the date of landing counts.
However, cutting it so close that whether or not this or that particular day counts is risky. So risky as to be foolish.
In this regard some reminders:
-- February 29, 2012 does NOT count.
-- As of the fifth year anniversary of the date of landing, the rolling five year period begins, and thus for someone who landed in June 2010, days present in 2010 begin to fall out of the calculation as the same date in 2015 is reached, thus --
-- -- as of the fifth year anniversary of the date of landing, the date of landing for sure will not count because it is outside the relevant five year time period
-- -- and, likewise, no date in June 2010 will count after the same day of the month in June 2015; and so on
Additionally, it is not what you know, but what the evidence shows, and a lot of the evidence is subject to interpretation and inference. It is very easy to infer that someone who was outside Canada most of the time, such as a PR outside Canada for more than 1000 days in a five year period, say, outside Canada 1090 days compared to, as claimed say 735 days in Canada, quite possibly was outside Canada more than the individual is acknowledging, unless there is strong evidence to document presence for those 735 days.
Not too long ago CBSA and even CIC seemed to be fairly liberal, if not lenient, in how they assessed a PR's compliance with the residency obligation. The trend, however, appears to be toward more strict scrutiny and enforcement. Thus, again, cutting it close to the 730 minimum can be rather risky.