Originally Posted by VE105

For the 1st meal seems it's based on time of the origin (midnight flights-supper, late-afternoon/evening flights-dinner, late morning to early afternoon departures-lunch).
For the 2nd meal I can't quite comprehend its logic. For Europe flights departing from Hong Kong which arrive at Europe in the morning, breakfast is served, so it seems that the 2nd meal is served based on time of destination. But for some flights arriving Hong Kong in the evening (such as CX885, arriving HKG at 18:55, *10 of following thread: flyertalk.com/forum/cathay-pacific-marco-polo-club/2002064-cx-j-menus-2020-a.html), breakfast is served as the 2nd meal.

Additionally, I recently read 2 flight reports on CX825 (approx. YYZ1415 – 1855+1HKG). The first one, in which the writer travelled in June 2018, lunch and dinner were served.
(travelupdate.com/cathay-pacific-business-class-777-300er-toronto-hong-kong/)
However, on the Jan 2020 flight, lunch and breakfast were served instead. (travelupdate.com/review-cathay-pacific-business-class-a350-1000-toronto-to-hong-kong/)