Check out example codes for "c# half hour dropdown list". It will help you in understanding the concepts better.

Code Example 1

static void DisplaySlots(string format, TimeSpan slotLength, int slots)
{
    DateTime time = DateTime.Today;
    for (int i = 0; i < slots; i++)
    {
        Console.WriteLine(time.ToString(format));
        time = time + slotLength;
    }
}

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