Does Anybody Really Know What Time It Is?

Not if they use this watch, they don't:

The EleeNo Bingo Watch has a series of tiny round windows laid out in a grid similar to a bingo game, where the outer dots show you the hours and the inner ones display the minutes. The only problem with that? There are just four minute indicators, forcing you to tell time in 15-minute increments.

I wonder if they also make a calculator that rounds everything to the nearest multiple of 10.