//we init this once so that if the function is repeatedly called
    //it isn't stressing the garbage man
    private static Regex r = new Regex(":");

    //retrieves the datetime WITHOUT loading the whole image
    public static DateTime GetDateTakenFromImage(string path)
    {
        using (FileStream fs = new FileStream(path, FileMode.Open, FileAccess.Read))
        using (Image myImage = Image.FromStream(fs, false, false))
        {
            PropertyItem propItem = myImage.GetPropertyItem(36867);
            string dateTaken = r.Replace(Encoding.UTF8.GetString(propItem.Value), "-", 2);
            return DateTime.Parse(dateTaken);
        }
    }

Image myImage = Image.FromFile(@"C:tempIMG_0325.JPG");
PropertyItem propItem = myImage.GetPropertyItem(306);
DateTime dtaken;

//Convert date taken metadata to a DateTime object
string sdate = Encoding.UTF8.GetString(propItem.Value).Trim();
string secondhalf = sdate.Substring(sdate.IndexOf(" "), (sdate.Length - sdate.IndexOf(" ")));
string firsthalf = sdate.Substring(0, 10);
firsthalf = firsthalf.Replace(":", "-");
sdate = firsthalf + secondhalf;
dtaken = DateTime.Parse(sdate);

// Read all metadata from the image
var directories = ImageMetadataReader.ReadMetadata(stream);

// Find the so-called Exif "SubIFD" (which may be null)
var subIfdDirectory = directories.OfType<ExifSubIfdDirectory>().FirstOrDefault();

// Read the DateTime tag value
var dateTime = subIfdDirectory?.GetDateTime(ExifDirectoryBase.TagDateTimeOriginal);

var directories = JpegMetadataReader.ReadMetadata(stream, new[] { new ExifReader() });

//retrieves the datetime WITHOUT loading the whole image
    public static DateTime GetDateTakenFromImage(string path)
    {
        using (FileStream fs = new FileStream(path, FileMode.Open, FileAccess.Read))
        using (Image myImage = Image.FromStream(fs, false, false))
        {
            PropertyItem propItem = null;
            try
            {
                propItem = myImage.GetPropertyItem(36867);
            }
            catch { }
            if (propItem != null)
            {
                string dateTaken = r.Replace(Encoding.UTF8.GetString(propItem.Value), "-", 2);
                return DateTime.Parse(dateTaken);
            }
            else
                return new FileInfo(path).LastWriteTime;
        }
    }