And one more note about leaving a buffer... Even if you think you've got *everything* correct, there could still be some mistakes that swing things by a day on any given trip. Have you ever...
- Had a flight that was supposed to arrive late on one day, but got delayed until the next?
- Had a flight that landed at the end of one day, but didn't go through customs until after midnight?
- Taken a trip to the states but didn't realize you didn't cross the border back into Canada until 2am the next day?
- Had any delays/cancellations/rerouting of flights that caused you to spend an extra night somewhere that your flight receipts don't show?
Any of those things (and probably more I can't think of) could have easily happened and put your calculation off by a day on any trip. Have it happen on enough trips, and there goes even a week buffer without any effort. For example, in my calculations, I had a Cathay Pacific flight that landed back in Canada just before midnight each time. I took that flight 4 times. I guarantee you I didn't get processed as re-entering Canada until the next day each of those times. That's *four* extra days right there that you wouldn't think of if you just looked at your calendar/flight receipts.
This is not a big deal if you have a buffer, as anyone looking at your file is going to understand a discrepancy with arrivals right around midnight. But if you don't have a buffer, the physical presence test is incredibly strict. You either meet it or you don't.
So, again, *at least* two weeks buffer before mailing the application. Think of it this way, it's better to wait a few weeks than do what I did. I now might lose my fee, have to wait weeks (maybe a month) before my application is officially withdrawn, then pay and mail my application again. This will likely put me more than a month or so behind, plus possibly trigger extra scrutiny.
So, buffer it.