How to call items at specific time in timers

Question

I have to start timer at 12AM daily. It has to execute 4 items i have with 15min interval

i.e, item1 should be executed @12, item2 @12 15 and so on

i have written below code:

To start timer @12Am :-

private void SetTimerValue()

{

//// trigger the event at 12 AM.

DateTime requiredTime = DateTime.Today.AddHours(0).AddMinutes(00);

if (DateTime.Now > requiredTime)

{

requiredTime = requiredTime.AddDays(1);

}

TimeSpan periodTS = requiredTime - DateTime.Now;

myTimer = new System.Threading.Timer(new TimerCallback(TimerAction), null, 0, (long)periodTS.TotalMilliseconds);

}

In TimerAction i have 4 items which has to be called @ 15min interval

public void TimerAction(object e)

{

var collection = new List<string> { "item1", "item2", "item3", "item4" };

// When timer is 12am, execute item1

// When timer is 12 15am, execute item2

// When timer is 12 30am, execute item3

// When timer is 12 45am, execute item4

}

My question is :

1. Can i create seperate timer inside TimerAction method?

2. How should i loop and execute all these 4 items?

3. Is there any better approach?. Please guide me to do this.