You are welcome to answer questions posted in the Ask a Teacher forum as long as your suggestions, help, and advice reflect a good understanding of the English language. If you are not a teacher, you will need to state that clearly at the top of your post. Please note, all posts are moderated by our in-house language experts, so make sure your suggestions, help, and advice house the kind of information an international language teacher would offer. If not, and your posts do not contribute to the topic in a positive way, they will be subject to deletion.
Basically "to pass the time of day" means to speak to someone, so the song is saying the other person is no longer speaking to the singer - he ignores her when they meat.
My interpretation is that the couple have grown apart as they grow up, and he no longer speaks to her ["ask the time of day" really means the same as "pass the time of day" - both are indicating communication], though she still feels strong feelings for him.
As so often with this kind of song, the syntax makes interpretation difficult since the writer is fitting words to music.