Amusingly, one of my kids gets very frustrated with how I answer what time it is on most requests. Most of my answers will be of what the nearest relevant time is. I will never bother determining what the exact minute is from my watch. As I just can't see the value of that. Even from a digital watch, I don't see the need in giving a majorly different answer to the same question within 5 minutes or so.
That's how people commonly give time in my language, I suspect mainly out of convenience:
Quarter hour precision is possible to achieve with at most five syllables (and typically just two); compare that to minute-level precision, which usually takes at least 5 and sometimes as many as 10.
Interestingly, spoken times also commonly use the 12 hour clock, while times are almost exclusively written as 23 hours.
I was always annoyed at my parents for doing this when I was a kid. When anyone asks me the time I always read out the minutes for whatever time my phone shows me. Maybe someone wants to make a particular bus or train and the more precise timing is appreciated, who knows!
