RTC Usage

AIBOX-9075 has RTC chip.

The RTC chip is one of the most widely used consumer electronic
products. It provides an accurate time reference for electronic
systems. Most RTC chips use high-precision crystal oscillators as
their clock sources.

The RTC chip is equipped with a battery/supercapacitor. In the event
of a loss of main power supply, the chip can still operate for a
certain period of time.

Time Read and Write

Use "hwclock" command can operate RTC:

   # Read current RTC time
   sudo hwclock
   2026-06-03 08:48:26.093819+00:00

   # Set RTC time directly
   sudo hwclock --set --date="20260603 15:00:00"

Sync with System Time

"date" command can show current system time, we recommend setting
system first, then sync to RTC.

   # Set system time
   date -s "20260603 15:00:00"

   # Sync system time to RTC
   hwclock -w

   # Set system time from RTC
   hwclock -s

Sync with Internet

When the device is connected to the network, wait for a few minutes.
The background service will automatically update the system time and
RTC time.

Use "timedatectl" to check the time sync status:

   firefly@ubuntu:~$ timedatectl
                  Local time: Wed 2026-06-03 15:28:33 CST
              Universal time: Wed 2026-06-03 07:28:33 UTC
                    RTC time: Wed 2026-06-03 07:28:32
                   Time zone: Asia/Shanghai (CST, +0800)
   System clock synchronized: yes
                 NTP service: inactive
             RTC in local TZ: no