Missing iCal calendars and data recovery

I had set up specific calendars on ICal (eg Birthday) but they just disappeared! I just have basic Calendar now (personal, important, and two more ) with no lost data. How is it possible? Can I recover my missing calendars data? I tried the back up on ICloud but recovery calendar not older than a week.

[Re-Titled by Moderator]

Original Title: Problem with Icalendar