The RTC
feature indicates whether a real-time clock (RTC) device is present on the target machine. When this feature is set, and an RTC is present on the target, the DATE
feature will retrieve time information from the RTC. If the RTC
feature is not set, indicating an RTC is not present on the target, the DATE
feature will emulate the RTC in software.
For more information, see RTC(5FEA).