As JPBless pointed out, you had to "Make sure that the following
dates are all the same:
- Date of application used in this calculation;
- Date of signature on this physical presence calculator print out;
- Date of signature on the form for Application for Canadian Citizenship - Adults"
Therefore, you shouldn't be surprised if they return your package. However, it is my opinion (which really does not matter) the premise of the instruction is based on the possibility of not having enough buffer days and for coherence from the processing agent point of view. You have more than 300 days... agents tend to be lenient for mistakes that specifically relate to eligibility days when you have a lot of buffer days. Hopefully, your file does not find one of those meticulous/anal retentive person in Sydney. I've made a few mistakes in my calculator (missed couple trips) but I'm now waiting for Oath.
Good luck!
P.S. you won't be able to retrieve the package from the courier. It's illegal with Canada Post.
However, if you are nervous and want peace of mind, you can resend the application with the correct date using the same payment receipt with a letter explaining what you did.
