As a wise man once said, "Nothing is over until we decide it is." Which apparently includes a marriage. For, as Justice Ikola (rightly) holds here, once the spouses decide that it's over, it is indeed over. Even if no one else knows. The date of your separation is the date you actually separated, not the date upon which you revealed your separation to the world.
That's the moral -- indeed, holding -- of the sad story of Samuel and Maureen Manfer. Who had an argument one week after their 31st wedding anniversary, at which point Samuel promptly moved out of the house and Maureen concluded that the marriage was finally over. (It sounds like this did not come as a shock to either party, as Samuel had already leased a separate apartment prior to the argument.) However, even though all these events transpired in June 2004, Maureen and Samuel decided to "keep up appearances" until after the holidays (! -- remember, this is all the way back in June), principally so their three daughters wouldn't find out. So they went on trips together, continued to have social contacts, and the like. But didn't live together. And no sex.
So Maureen says the date of separation is June 2004. But Samuel says that the date of separation is March 2005, the date upon which they revealed their separation to the world. (The fight, of course, is all about money, since after the date of separation, the money a spouse earns is his and her own.)
The trial court agrees with Samuel, but Justice Ikola agrees with Maureen, and reverses. Once you decide it's over, and in fact separate, it doesn't matter who you tell. Or who you don't tell. It's over.