CSA Staff Notice 55-316 Questions and Answers on Insider Reporting and SEDI
4 Insider Information
4.2 Insider Profile
Section 4.2.12

What Date Do I Report: An Opening Balance Date Or The Date I Became A Reporting Insider?

If you have not previously filed an insider report for the issuer, enter the date on which you became an insider of this issuer.

If you have previously filed an insider report for this issuer, enter the opening balance date. This date will be used for all opening balances for this issuer and should be prior to the date of any transactions required to be reported for this issuer on SEDI.