How to adjust the 24-hour calendar?

Set the calendar to a 24-hour clock, and then press the up key or the B key until it is switched to 12/24-hour clock.

The perpetual calendar is the oldest solar calendar in ancient legends of China. A perpetual calendar is an annual calendar that records the dates of specific solar and lunar calendars within a certain time range (such as 100 years or more), which is convenient for people in need to query and use. Ten thousand years is just a symbol, indicating a long time span. The perpetual calendars used now include calendars of several years or calendars suitable for several years. Modern perpetual calendars can display various calendars such as solar calendar, lunar calendar, and dry calendar at the same time, and can also contain various functional information such as good or bad luck, holidays, reminders, etc., which is very convenient for people to query and use.