job.js

Parse.Cloud.job("incomingEventNotification", function () {
    Parse.Cloud.useMasterKey();

    var query = new Parse.Query("Event");
    query.greaterThan("limit", 1);
    query.equalTo("notifiedAboutUpcomingEvent", false);
    query.find().then(function(results) {
        //get the event
        for (var event in results) {
            for (var userID in event.object.get("attendeeIDs")) {
                var pushQuery = new Parse.Query(Parse.Installation);
                pushQuery.equalTo('channels', userID);
                var eventName = event.object.get("summary");
                Parse.Push.send({
                    where: pushQuery,
                    data: {
                        alert: eventName + ", " + "starting in 24 hours"
                    },
                }, {
                    success: function (success) {
                        // Push was successful
                        event.set("notifiedAboutUpcomingEvent", true)
                        event.save()
                    },
                    error: function (error) {
                        throw "Got an error " + error.code + " : " + error.message;
                    }
                }
            }
        }
    }
});
});