I have fixed my problem with below code:
NSMutableArray *datearray=[NSMutableArray array];
NSCalendar *calendar = [[NSCalendar alloc] initWithCalendarIdentifier:NSGregorianCalendar];
NSDateComponents *todayComponents = [[NSDateComponents alloc] init];
NSArray *myStringArr=[self.CalenderDays objectAtIndex:0];
for(int i=0; i<myStringArr.count; i++){
todayComponents.year = [[calElem year]intValue];
todayComponents.month = [[calElem month] intValue];
todayComponents.day = [[myStringArr objectAtIndex:i]intValue];
todayComponents.hour = 00;
todayComponents.minute = 00;
todayComponents.second= 00;
NSDate *today = [calendar dateFromComponents:todayComponents];
[datearray addObject:[self getdateCalendar:today]];
}