Register this webservice
http://www.webservicex.net/sendsms.asmx[
^]
Then, in your code add a timer control
then on the tick event send the sms after checking the time
like
Timer1_Tick(()
{
if(DateTime.Now == 'time you want the SMS to be sent')
{
semdsms obj = new sendsms();
obj.SendSMSToIndia(params);
}
}
obj is the webservice object
and you would have to keep the application running