I hope someone here can help me with a question that I have had for ages, but can't find an answer to. When I ask my Japanese friends I just get a blank look! In sentences where one is talking about elapsed time for example:
彼女に最後に会ってから１０年になります。 It is 10 years since I last saw her.
All the examples I find in the dictionary use になります、not なりました。The 'becoming 10 years' has already occurred, it is in the past, so why isn't it expressed using the past tense? I find it particularly confusing, because if I used a different verb to express the passing of time, then it would be past tense, e.g.
この前彼に会ってから５年がたちました。 It's been five years since I last saw him.
This maybe one of this things that I just have to accept as 'that is how Japanese works', but if there is some sort of logical explanation, I would be very glad to hear it. よろしくお願いします。