use expo-calendar.createEventAsync() return fail

  1. SDK Version: “expo”: “~38.0.8”,
    “expo-calendar”: “~8.2.2”,
  2. Platforms(Android/iOS/web/all): iOS

I use Calendar.createEventAsync () to create Event.

const taskId = await Calendar.createEventAsync(
task.calendarId,
{
title: task.title,
startDate: task.startDate,
endDate: task.endDate,
alarms: [{relativeOffset: task.alarmTime}],
allDay: task.allDay,
notes: task.notes,
timeZone: task.timeZone,
location: task.locationAddress,
recurrenceRule: task.recurrenceRule
}
)

It works well until i try to create monthly recurrence Event. I know the problem is come from ‘recurrenceRule’. But i don’t what is wrong.

When createEvent for weekly recurrent, it works well by following recurrentRule:
recurrentRule: Object {
“daysOfTheWeek”: Array [
Object {
“dayOfTheWeek”: 2,
},
Object {
“dayOfTheWeek”: 3,
},
],
“frequency”: “weekly”,
“interval”: 1,
}

But it was fail when i create monthly event by following recurrentRule:
recurrentRule: Object {
“daysOfTheMonth”: Array [
18,
19,
],
“frequency”: “monthly”,
“interval”: 1,
}

can someone tell me what is wrong with the monthly recurrentRule. thanks