Get timestamp of images in Photo Library using ALAssetLibrary - ios

Question

I am trying to display images from photo library along with time stamp(the time when the were created or modified). I have fetched the images using following code. How can I get their time stamp correctly? here is the code:
-(void)getAllPictures{
imageArray=[[NSArray alloc] init];
mutableArray =[[NSMutableArray alloc]init];
NSMutableArray* assetURLDictionaries = [[NSMutableArray alloc] init];
library = [[ALAssetsLibrary alloc] init];
void (^assetEnumerator)( ALAsset *, NSUInteger, BOOL *) = ^(ALAsset *result, NSUInteger index, BOOL *stop) {
if(result != nil) {
if([[result valueForProperty:ALAssetPropertyType] isEqualToString:ALAssetTypePhoto]) {
[assetURLDictionaries addObject:[result valueForProperty:ALAssetPropertyURLs]];
NSURL *url= (NSURL*) [[result defaultRepresentation]url];
[library assetForURL:url
resultBlock:^(ALAsset *asset) {
[mutableArray addObject:[UIImage imageWithCGImage:[[asset defaultRepresentation] fullScreenImage]]];
if ([mutableArray count]==count)
{
imageArray=[[NSArray alloc] initWithArray:mutableArray];
[self allPhotosCollected:imageArray];
}
}
failureBlock:^(NSError *error){ NSLog(#"operation was not successfull!"); } ];
NSLog(#"ali: %#",result);
}
}
};
NSMutableArray *assetGroups = [[NSMutableArray alloc] init];
void (^ assetGroupEnumerator) ( ALAssetsGroup *, BOOL *)= ^(ALAssetsGroup *group, BOOL *stop) {
if(group != nil) {
[group enumerateAssetsUsingBlock:assetEnumerator];
[assetGroups addObject:group];
count=[group numberOfAssets];
}
};
assetGroups = [[NSMutableArray alloc] init];
[library enumerateGroupsWithTypes:ALAssetsGroupAll
usingBlock:assetGroupEnumerator
failureBlock:^(NSError *error) {NSLog(#"There is an error");}];}
-(void)allPhotosCollected:(NSArray*)imgArray{
//write your code here after getting all the photos from library...
NSLog(#"all pictures are %#",imgArray);
for (int i=0; i<imgArray.count; i++) {
UIImageView *img=[[UIImageView alloc] initWithImage:imgArray[i]];
img.frame=CGRectMake(10, 20+105*i, 200, 100);
[self.view addSubview:img];
}
}

Answer 1

To get Time Stamp Use This:
NSDate *date = [asset valueForProperty:ALAssetPropertyDate];