Date predicate does not work

问题:

All Objects from core data

{
    dtStartDate = "Jun 10, 2016-10:40 AM";
},
{
    dtStartDate = "May 12, 2016-06:55 AM";
},
{
    dtStartDate = "May 12, 2016-08:05 AM";
},
{
    dtStartDate = "May 12, 2016-02:30 PM";
},
{
    dtStartDate = "Jun 12, 2016-07:50 AM";
},
{
    dtStartDate = "Jul 12, 2016-08:50 AM";
},
{
    dtStartDate = "Jun 12, 2016-07:50 AM";
},
{
    dtStartDate = "May 12, 2016-10:00 AM";
},
{
    dtStartDate = "Jun 12, 2016-07:30 AM";
}

I use this date format to predicate core data

NSDate *dt = [NSDate date];
NSDateFormatter *df =[[NSDateFormatter alloc] init];
[df setDateFormat:@"MMM dd, yyyy-hh:mm a"];
NSString *today =[df stringFromDate:dt];
NSDate *dateOfToday = [df dateFromString:today];
NSMutableArray *meetings=nil;

Now i have two conditions Fetch Date of future (including Current) and fetch date of past

Fetch Date of Future (including Today)

  NSPredicate *predicate = [NSPredicate predicateWithFormat:@"dtStartDate >=  %@",dateOfToday];
   NSMutableArray *meetingsArr = [[CoreDataAPI sharedInstance] checkForRecordExistInTable:@"Tbl_Meeting" withCompountPredicate:[NSArray arrayWithObjects:predicate, nil]];

Return 9 Object (ALL) WRONG

   NSPredicate *predicate = [NSPredicate predicateWithFormat:@"dtStartDate <= %@",dateOfToday];

   NSMutableArray *meetingsArr = [[CoreDataAPI sharedInstance] checkForRecordExistInTable:@"Tbl_Meeting" withCompountPredicate:[NSArray arrayWithObjects:predicate, nil]];

Return 0 Object (nil) WRONG

Please help me to solve it Thanks in Advance

i can manually do it with this method and working. But i only want to do with predicate

-(NSMutableArray *)filterMeetingsBasedOnTime:(BOOL)isPastMtng :(NSMutableArray*)arr
{
NSDate *dt = [NSDate date];
NSDateFormatter *df =[[NSDateFormatter alloc] init];
[df setDateFormat:@"MMM dd, yyyy-hh:mm a"];


NSMutableArray *arrMeeting = [[NSMutableArray alloc] init];

for(NSDictionary *sMtngDict in arr)
{
    NSDate  *meetDate = [df dateFromString:[sMtngDict valueForKey:@"dtStartDate"]];

    if(isPastMtng)
    {
        if([meetDate timeIntervalSinceDate:dt]<0)
        {
            [arrMeeting addObject:sMtngDict];
        }
    }
    else{
        if([meetDate timeIntervalSinceDate:dt]>=0)
        {
            [arrMeeting addObject:sMtngDict];
        }
    }
}

return arrMeeting;
}

can we use this method logic in predicate if yes then how ?