An Image can contain additional Information about the Camera or the Date it was taken. It’s quite easy to access those Information with C-Sharp. All you need to do is to add a Reference to PresentationCore and WindowsBase, include the System.Windows.Media.Imaging Namespace and use the following Code-Snippet as a StartingPoint:

public DateTime GetDateTaken(string filePath)
{
    using (FileStream fileStream = new FileStream(filePath, FileMode.Open, FileAccess.Read))
    {
        BitmapFrame bitmapFrame = BitmapFrame.Create(fileStream, BitmapCreateOptions.DelayCreation, BitmapCacheOption.None);
        BitmapMetadata bitmapMetadata = bitmapFrame.Metadata as BitmapMetadata;
        return DateTime.Parse(bitmapMetadata.DateTaken);
    }
}