Military time
Here's a chart that shows regular times on a 12-hour clock next to their 24-hour clock times. This chart can help you understand how to change times from the regular clock to the 24-hour clock. You can use it to learn military time easily.
Military to civilian time
Civilian to military time

How to Read Military Time
In this way of telling time, the day begins at midnight, which is shown as 00:00. The last minute before the next day starts is 23:59. Sometimes, you might see midnight written as 24:00. Both ways are correct.
Here's an example to help you understand the difference between the regular 12-hour clock and military time: Imagine a schedule from 4:00 PM to midnight. In military time, that's from 16:00 to 24:00. Another example is 10:15 AM, which is the same, 10:15, in military time. However, 2:30 PM would be shown as 14:30.