 public
 extension DateTransform {
 
+    /// Date transformation working with dates formatted using ISO 8601 standard.
+    /// - Note: Transformation covers only `yyyy-MM-dd'T'HH:mm:ssZZZZZ` format.
     public
     static var ISO8601: DateTransform {
         let formatter = NSDateFormatter()

import var   Foundation.NSCalendarIdentifierISO8601
import class Foundation.NSLocale

public
struct DateTransform: TransformType {

    private
    let formatter: NSDateFormatter

    public
    init(dateFormat: String) {
        let formatter = NSDateFormatter()

        self.init(formatter: formatter)
    }

    /// Creates an instance of `DateTransform` initilized with given date formatter.
    /// - Parameter formatter: Date formatter.
    public
    init(formatter: NSDateFormatter) {
        self.formatter = formatter.copy() as! NSDateFormatter
    }

    /// Transforms node to `NSDate` value.
    /// - Parameter node: Node.
    /// - Returns: `NSDate` instance.
    /// - Throws: `MappingError`, `TransformError` if `String` value of node does not represent correctly formatted date.
    public
    func applyToNode(node: NodeType) throws -> NSDate {
        guard let value = try formatter.dateFromString(node.value(String)) else {
