I have a PIC18F47J53 with an RTCC. The datasheet shows an RTCCIE bit in the PIE3 register and a corresponding interrupt flag but curiously these bits aren't mentioned anywhere else in the datasheet.
The alarm section does have this very cryptic reference on interrupts.
17.3.2 ALARM INTERRUPT
At every alarm event, an interrupt is generated. Additionally,
an alarm pulse output is provided that operates
at half the frequency of the alarm.
The alarm pulse output is completely synchronous...
RTCC Interrupt on PIC18F47J53
The alarm section does have this very cryptic reference on interrupts.
17.3.2 ALARM INTERRUPT
At every alarm event, an interrupt is generated. Additionally,
an alarm pulse output is provided that operates
at half the frequency of the alarm.
The alarm pulse output is completely synchronous...
RTCC Interrupt on PIC18F47J53