so we could say ' I go to bed at 7 o'clock PM '. 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 ...

It is a 12-hour clock. The first 12 hours of the day, from midnight to midday, are called am. The next 12 hours, from midday to midnight, are called pm. However, you can tell the time without ...