iCloud different than IOS devices

This post is primarily about the syncing of iCal. For some reason all of my events from iCal that are on the iCloud website and on my iMac are not appearing on my iPhone or iPad. I have multiple calendars checked to appear on all of my devices. All of the missing appointments are from the same calander. The odd thing is that not all of the events in that calander are missing. Only some days are missing. This happens until the month of May on my calanders. The problem is I need the past info. I have checked to make sure all accounts are with the same user and that all calanders are either checked or switched on. Any suggestions?