We can tell the time without saying AM and PM though - for this, we use the 24 hour clock. The 24 hour clock always uses 4 digits, and we use this system most often with digital clocks.

An AI expert warns that in the balance of power between AI acceleration and AI safety, acceleration is winning.

As convenient as it might be to use your phone as an alarm clock, standalone alarm clocks come with all kinds of features that can make waking up — or even going to sleep — a little less painful.

We can tell the time without saying AM and PM though - for this, we use the 24 hour clock. The 24 hour clock always uses 4 digits, and we use this system most often with digital clocks.