Time mirrors are useful to know if youll cut yourself shaving tomorrow.

(This is not an endorsement of Future Mirrors Inc.)

One could use it to make their day to day life less petty and boring by expanding their knowledge and their intellectual horizons, and thinking about beyond the limited necessities or niceties of their "day to day life".

Can't tell if you're trolling. Surely you've heard of the concept where people look into stuff before realising it's something we can practically use today? Like, before electricity was discovered, nobody could possibly have known the force existed, let alone what they could use it for and this whether/how useful it was going to be

Among the first reasons for getting electricity was light. It took many centuries to go from "huh, this metal behaves odd when I put it in a jar of acid" (around the year 200) to light bulbs being invented to them making it into your day-to-day life around the year 1880 (if you were a rich person in the right country)

You shouldn't wear your ignorance with such pride.

Only time will tell

If you have to ask....