Get Random integer value C#

Why using the method RandomBool(), I always get 1? Please, help fix the second method.

static class Tools
{
    public static int RandomNumber(int end)
    {
        var rand = new Random(DateTime.Now.Millisecond);
        return rand.Next(0, end);
    }

    public static bool RandomBool()
    {
        if(RandomNumber(1) == 0)
            return true;
        else 
            return false;
    }
}