Accessing Base Class Member In Masked Derived Class in C#

using System;
class Time {
    public byte hour {
        set;
        get;
    }
    public byte minute {
        set;
        get;
    }
    public void SetTime(byte hour, byte minute) {
        this.hour = hour;
        this.minute = minute;
    }
    public void DisplayTime() {
        Console.Write(hour + ":" + minute);
    }
}
class NewTime: Time {
    public byte second {
        set;
        get;
    }
    public void SetTime(byte hour, byte minute, byte second) {
        SetTime(hour, minute);
        this.second = second;
    }
    new public void DisplayTime() {
        base.DisplayTime();
        Console.Write(":" + second);
    }
}
class UsingTime {
    static void Main(String[] arg) {
        Console.WriteLine("Base Time Class");
        Time hmt = new Time();
        hmt.SetTime(12, 22);
        Console.Write("Time of HMT: ");
        hmt.DisplayTime();
        Console.WriteLine("\n\nDerived Time Class");
        NewTime sonata = new NewTime();
        Console.Write("Time of SONATA: ");
        sonata.SetTime(10, 15, 30);
        sonata.DisplayTime();
    }
}