The expression "a quarter till 9" or "a quarter to 9" is a colloquial way of indicating the time, and it is widely used in spoken English. The reason people don't typically say "8:75" is because the standard timekeeping convention divides an hour into 60 minutes, not 100. Therefore, it's more common to use terms like "quarter" or "half" when referring to time intervals that represent a fraction of an hour.
Here's a breakdown of the time expressions:
- "A quarter till 9" means 15 minutes before 9 o'clock (15 minutes before 9:00), which is equivalent to 8:45.
- "A quarter to 9" also means 15 minutes before 9 o'clock, so it is also equivalent to 8:45.
Using the standard time format with hours and minutes allows for clear communication and is more intuitive for most people since we are accustomed to using this system for telling time. While "8:75" technically represents the same time as "a quarter till 9," it is not a standard or conventional way to express time in English.