Vulcan/packages/telescope-newsletter/lib/server/cron.js

Later = Npm.require('later');

defaultFrequency = 7; // once a week

getSchedule = function (parser) {
  var frequency = getSetting('newsletterFrequency', defaultFrequency);
  switch (frequency) {
    case 1: // every day
    // sched = {schedules: [{dw: [1,2,3,4,5,6,0]}]};
    return parser.recur().on(1,2,3,4,5,6,0).dayOfWeek();

    case 2: // Mondays, Wednesdays, Fridays
    // sched = {schedules: [{dw: [2,4,6]}]};
    return parser.recur().on(2,4,6).dayOfWeek();

    case 3: // Mondays, Thursdays
    // sched = {schedules: [{dw: [2,5]}]};
    return parser.recur().on(2,5).dayOfWeek();

    case 7: // Once a week (Mondays)
    // sched = {schedules: [{dw: [2]}]};
    return parser.recur().on(2).dayOfWeek();

    default: // Don't send
    return null;
  }  
}

SyncedCron.getNext = function (jobName) {
  var scheduledAt;
  try {
    this._entries.some(function(entry) {
      if(entry.name === jobName){
        var schedule = entry.schedule(Later.parse);
        scheduledAt = Later.schedule(schedule).next(1);
        return true;
      }
    });
  } 
  catch (error) {
    console.log(error)
    scheduledAt = 'No job scheduled';
  }
  return scheduledAt;
}

getNextCampaignSchedule = function () {
  return SyncedCron.getNext('Schedule newsletter');
}

SyncedCron.add({
  name: 'Schedule newsletter',
  schedule: function(parser) {
    // parser is a later.parse object
    // var sched;
    return getSchedule(parser)
    
  }, 
  job: function() {
    scheduleNextCampaign();
  }
});

Meteor.startup(function() {
  if(getSetting('newsletterFrequency', defaultFrequency) != 0) {
    SyncedCron.start();
  };
});

Meteor.methods({
  getNextJob: function (jobName) {
    return SyncedCron.getNext(jobName);
  }
});