RTC
From FriendlyELEC WiKi
1 S5P4418/S5P6818/RK3399
1.1 Read current datetime
sudo hwclock -r -f /dev/rtc0
The output results are summarized below:
Tue 01 Sep 2009 12:07:52 AM UTC .371098 seconds
1.2 Set and save datetime
sudo date -s "2020-04-20 11:03:00" sudo hwclock -w -f /dev/rtc0