How to switch between 12/24 hour format RTC DS1307
I too is one who has found this difficult. But when I see this forum it looks like some one showing the color of milk to blind. Why not give the details from start to the end without giving so many problems, rather than trying to be smart and wise.
The DS1307 can be run in either 12-hour or 24-hour mode. Bit 6 of the hours register is defined as the 12-hour or 24-hour mode-select bit. When high, the 12-hour mode is selected. In the 12-hour mode, bit 5 is the AM/PM bit with logic high being PM.