iOS - How to selectively delete files older than a month in Documents Directory

I am downloading images to my app which after a few weeks the user will not care about. I download them to the app so they will not have to be downloaded every launch. The problem is I do not want the Documents folder to get bigger than it has to over time. So I thought I could "clean up" file older than a Month.

The problem is, there will be a few files in there that WILL be older than a month but that I do NOT want to delete. They will be Static Named files so they will be easy to identify and there will only be 3 or 4 of them. While there might be a few dozen old files I want to delete. So heres an example:

picture.jpg           <--Older than a month DELETE
picture2.jpg          <--NOT older than a month Do Not Delete
picture3.jpg          <--Older than a month DELETE
picture4.jpg          <--Older than a month DELETE
keepAtAllTimes.jpg    <--Do not delete no matter how old
keepAtAllTimes2.jpg   <--Do not delete no matter how old
keepAtAllTimes3.jpg   <--Do not delete no matter how old

How could I selectively delete these files?

Thanks in advance!

Solution

Code to delete files which are older than two days. Originally I answered here. I tested it and it was working in my project.

P.S. Be cautious before you delete all files in Document directory because doing so you might end up losing your Database file(If you are using..!!) there which may cause trouble for your Application. Thats why I have kept if condition there. :-))

// Code to delete images older than two days.
   #define kDOCSFOLDER [NSHomeDirectory() stringByAppendingPathComponent:@"Documents"]

NSFileManager* fileManager = [[[NSFileManager alloc] init] autorelease];
NSDirectoryEnumerator* en = [fileManager enumeratorAtPath:kDOCSFOLDER];    

NSString* file;
while (file = [en nextObject])
{
    NSLog(@"File To Delete : %@",file);
    NSError *error= nil;

    NSString *filepath=[NSString stringWithFormat:[kDOCSFOLDER stringByAppendingString:@"/%@"],file];


    NSDate   *creationDate =[[fileManager attributesOfItemAtPath:filepath error:nil] fileCreationDate];
    NSDate *d =[[NSDate date] dateByAddingTimeInterval:-1*24*60*60];

    NSDateFormatter *df=[[NSDateFormatter alloc]init];// = [NSDateFormatter initWithDateFormat:@"yyyy-MM-dd"];
    [df setDateFormat:@"EEEE d"]; 

    NSString *createdDate = [df stringFromDate:creationDate];

     NSString *twoDaysOld = [df stringFromDate:d];

    NSLog(@"create Date----->%@, two days before date ----> %@", createdDate, twoDaysOld);

    // if ([[dictAtt valueForKey:NSFileCreationDate] compare:d] == NSOrderedAscending)
    if ([creationDate compare:d] == NSOrderedAscending)

    {
        if([file isEqualToString:@"RDRProject.sqlite"])
        {

            NSLog(@"Imp Do not delete");
        }

        else
        {
             [[NSFileManager defaultManager] removeItemAtPath:[kDOCSFOLDER stringByAppendingPathComponent:file] error:&error];
        }
    }
}