The status bar at the top of my Samsung S9+ does not show the am/pm after the time. The picture below was taken at 3:23 pm local time but you would not know that unless I told you. It could be 3:23 am. If I were using a 24-hour clock, I would expect that there not be an am/pm. However, my time setting is for 12-hour clock and could have an am/pm. How do I add the am/pm after the time?
Some may say that I can easily tell whether it is am or pm... just look outside. That may be true at 3:23 am or pm. However, at 8 pm during the summer time, the sunlight is about the same whether it is morning or evening. I would have to walk outside to find the sun and then know. During the winter time, 6 am and pm is completely dark. There is no sun to help me know.
Let's say I am very tired during the winter and start a nap at 4 pm. I wake up at 6. I do not know if I slept for 2 hours or 14 hours. Most likely I slept for 2 hours but it depends on how much sleep debt I have.