What is the limit for Google calendar SMS notification per day?

How to detect I reached sms limit?

Google write only this:

http://www.google.com/support/calendar/bin/answer.py?hl=en&answer=36589

You might have reached the limit for SMS notifications. 
There is a limit to the number of SMS notifications you can receive each day. 
This limit shouldn't affect most users, but it's something to keep in mind if you've scheduled a large number of events and are no longer receiving SMS notifications.

I created sms reminder based on google calendar api(apps-script), but I think now I reached the daily limit for SMS notifications... but google not informed what is exactly amount of sms limit restriction :/

function emailNotification()
{
// POWIADOMIENIA SMS O NOWEJ POCZCIE
var calendarID = "[email protected]"; // id kalendarza o nazwie „sms4email”
var gmailLabelTODO = "autoscriptslabels/sms"; // etykieta „AutoScriptsLabels/SMS”
var gmailLabelDONE = "done/_sms"; // etykieta „DONE/_SMS”
var calendarEventDescription = "this-is-sms_notification-mark"; // etykieta utworzonego zdarzenia, dzieki której mozna bedzie je znalezc podczas kasowania

var calendar = CalendarApp.getCalendarById(calendarID); // otwieramy kalendarz

var threads = GmailApp.getUserLabelByName(gmailLabelTODO).getThreads(); // zmienna przechowujaca kolekcje lancuszków z etykieta TODO
var now = new Date();
if(threads == 0) return; // zaprzestanie wykonywania, jezeli brak nowych lancuszków

for(i in threads) // tworzymy zdarzenia
{
  var title = threads[i].getFirstMessageSubject(); // tytul emaila
  var startDate = new Date(now.getTime()+120000);
  var endDate = new Date(now.getTime()+120000);

  var messages = threads[i].getMessages();
  var senderEmail = messages[0].getFrom(); // nadawca emaila

  var advancedArgs = {location:senderEmail, description:calendarEventDescription};
  calendar.createEvent(title, startDate, endDate, advancedArgs);
}

Utilities.sleep(1000);
GmailApp.getUserLabelByName(gmailLabelDONE).addToThreads(threads); // dodawanie etykiety DONE
Utilities.sleep(1000);
GmailApp.getUserLabelByName(gmailLabelTODO).removeFromThreads(threads); // usuwanie etykiety TODO


Utilities.sleep(120000); // czekamy az kalendarz wysle SMS
var TodaysEvents = calendar.getEventsForDay(now);
for (i in TodaysEvents) // wyszukiwanie wedlug zdarzenia i kasowanie po wyslaniu
{
  if (TodaysEvents[i].getDescription()==calendarEventDescription)
  TodaysEvents[i].deleteEvent();
}
}