My 5 years since landing(Oct 22, 2016) is coming Oct 22, 2021. I will have been in Canada for nearly 750 days on Oct 22, 2021. I calculated using physical presence calculator (used for Citizenship) with every single trip I have made since landing.
So applying to sponsor today(Sep 29) should not cause issues since I am in compliant to satisfy 730 days in five since landing?
I do not wish to do your math for you because it is your life and your responsibility. You should also check the regs and requirements for yourself.
How it works: up to the anniversary of landing (and if you are in Canada), you can include the days from now to the fifth anniversary of landing. (Or conversely if you have been out of Canada less than 1095 days since landing). [Those days are 'included' for the purposes of calculating residency obligation, i.e. benefit of doubt that you will be in Canada for those days.]
BUT: I actually concur with
@scylla above in the conclusion - if it is literally ~a week or two until you will have enough days to meet the 730 days (without benefit of the days remaining until October 22), it is FAR more prudent to just wait a few weeks, including a bit extra. You don't want to be off by a day for some minor reason.
The consequences of getting it wrong, even through an inadvertent error, are quite serious, so take the extra time and check your application carefully. Note also that cases that are 'close' (and eg it doesn't seem clear sponsor is residing in Canada)
might get extra scrutiny and take longer.
