Given that the approvability test for “continuous ordinary residence” is essentially so flexible, it is reasonable to assume that the commencement date of the 7 years runs from the time that you first landed in Hong Kong and can objectively be assessed to have taken steps to lay down the foundations of your long term stay in the HKSAR.
For many foreign nationals, that will essentially mean having arrived here as a visitor then, after a few weeks or months, gone on to adjust visa status from non resident Visitor to resident employee, investor, dependant, student or special immigration programme participant.
However, in deciding just when the clock of formal residence in Hong Kong starts ticking the Immigration Department have adopted a very straight forward, easy to administer approach.
To avoid protracted arguments and documentation assessments as to when a foreign national applicant for the right of abode first landed in Hong Kong, the Hong Kong ID start counting from the day your residence visa was activated upon first arrival with that residence visa status.
So formal residence for the purposes of the 7 year clock starts on the commencement date of your arrival under your very first residence visa – and not before.