Date+ISO8601.swift

// ISO 8601 Extension for Swift to send dates to Ruby on Rails
extension Date {
    init(dateString:String) {
        self = Date.iso8601Formatter.date(from: dateString)!
    }

    static let iso8601Formatter: ISO8601DateFormatter = {
        let formatter = ISO8601DateFormatter()
        formatter.formatOptions = [.withFullDate,
                                          .withTime,
                                          .withDashSeparatorInDate,
                                          .withColonSeparatorInTime]
        return formatter
    }()
}

http://stackoverflow.com/questions/28016578/swift-how-to-create-a-date-time-stamp-and-format-as-iso-8601-rfc-3339-utc-tim#42101630