The Players (based on Raspberry Pi) do not have an RTC (Real Time Clock) module on board.
It's cost if fairly low (you can find them on eBay), but it is something that needs to be considered if your deployment is time-critical.
The Technical Details
Two clocks are important in Linux: the ‘hardware clock’, also known as RTC (Real Time Clock), CMOS or BIOS clock, and the 'system clock'.
- The RTC is a battery backed clock module connected on the GPIO ports of the Player (Raspberry Pi) that keeps time even when the Player is shut down (or has no power).
- The second clock is called the ‘system clock’, maintained by the operating system, Linux in our case
Without an RTC, the Player saves the current time on the SD card every hour. If there is a power failure, when the Player boots, it will load the last time recorded on the SD card. Then, it will sync its time from the Internet NTP (Network Time) servers, or as a backup, our servers. But if there is no Internet access, the Pi will not be able to sync time, so its clock might be off (from minutes, to hours, depending how long the power failure was). This will affect Scheduling, not content playback.
If time-scheduling is critical and you may have serious down-time in your Internet connection, then you might consider adding an RTC. Reach out if you need more details for your case.