Thanks for your question. I think, this post will remove your the dilemma of time in English.
Information about time:
firstly you should remember this word
1. Quarter – divide into four equal or corresponding parts. Example: peel and quarter the bananas.

2. Half – either of two equal or corresponding parts into which something is or can be divided. Example: “two and a half years”

3. Past – gone by in time and no longer existing. Example: the danger is now past

4. To – so as to be closed or nearly closed. Example: he pulled the door to behind him.

Consistently: First minute after calculating the hour.

1. It is fifteen past nine.
2. It is fifteen to nine.
3. It is quarter past nine.
4. It is quarter to nine.

Thanks, I think, this post will remove your the dilemma of time in English.