[SyncEvolution] sqlite calendar backend

Hello, how can i parse in sqlite calendar backend the fields of vcalendar especially the RRULE fields : to retrieve them i will try this for example : getSynthesisAPI()->getValue(aItemKey, "RR_FREQ", data6); // same things for other fields like : RR_INTERVAL,RR_FMASK,RR_LMASK,RR_END is there any way to retrieve RRULE fields clairely ? cause i don't understand the way how you retrieve MDay or week day or number of repetetion of the event using these fields of RRULE . THX.