I am trying to show the count in a label based on the time

Question

I am trying to show the count in a label based on the time using timespan

but label always null

 

while i am debugging the code there are showing the count value in the label but not on the browser

public partial class _Default : System.Web.UI.Page
{
public int j;
public int numoffers = 6000;
public int i;
protected void Page_Load(object sender, EventArgs e)
{
SetInterval(() => calculate(), TimeSpan.FromSeconds(10));
}
public void calculate()
{
DateTime time = DateTime.Now;
int hour = time.Hour;
int minute = time.Minute;
int second = time.Second;
int numofdays = 90;
int num = Check_Prime(minute);
int numofperday = numoffers / numofdays;
if (minute % 2 == 0)
{
j = j + 2;
i = numoffers - j;
}
else
{
if (num == 1)
{
j = j + 3;
i = numoffers - j;
}
else
{
j = j + 5;
i = numoffers - j;
}
}
if (j >=6000)
{
Thread.Sleep(TimeSpan.FromSeconds(100000));
}
Label2.Text = i.ToString();
}
public async Task SetInterval(Action action, TimeSpan timeout)
{
await Task.Delay(timeout).ConfigureAwait(false);
action();
SetInterval(action, timeout);
}
private int Check_Prime(int number)
{
int i;
for (i = 2; i <= number - 1; i++)
{
if (number % i == 0)
{
return 0;
}
}
if (i == number)
{
return 1;
}
return 0;
}
}