I got a nice e-mail from Bernie W., reminding me that annual inspections are actually due at the end of the 12th month following the date of the inspection, so it actually doesn't expire until the end of September. I had actually looked for that little detail a few months ago, and failed to find it then. Now that I looked again, I see that Bernie is correct. The info is in CAR Std 625.86, plain as day, at least if you are a lawyer. Thanks Bernie.

But, as Bernie also noted, things like the annual compass swing, ELT recerts, etc, do expire 12 months to the day after they were completed. So, I couldn't have flown yesterday anyway, as the compass swing had expired. I will do the last items on the annual inspection in early October, and signing it off in October rather than September will give me another month before I have to do it all over again.