As Hikey970 board could not save date to hardware, you must ntp the time by hand or added it to reboot script or crontab.
First, connect the board with the debug line, and use shell enters the os.
The sync time command is ntpdate ntp3.aliyun.com
Step1 modify startup script
modify the init.rc startup script in Android
add below command at the end of init.rc
ntpdate ntp3.aliyun.com
Step 2: add a crontab, and sync the time at 7:00 every morning.
echo ‘0 7 * * ntpdate ntp3. Aliyun. Com’ > > / data / crontab / root
Step3 start crontab
echo ‘crond – B – C / data / crontab’ > / system / etc / init.d/crond
chmod + X / system / etc / init.d/crond