I need a Nodejs scheduler that allows for tasks at different intervals

I've used node-cron and agenda.

node-cron is a very simple library, which provide very basic and easy to understand api like crontab. It doesn't need any config and just works.

var cronJob = require('cron').CronJob;
var myJob = new cronJob('00 30 11 * * 1-5', function(){...});
myJob.start();

agenda is very powerful and fit for much more complex services. Think about ifttt, you have to run millions of tasks. agenda would be the best choice.

Note: You need Mongodb to use Agenda

var Agenda = require("Agenda");
var agenda = new Agenda({db: { address: 'localhost:27017/agenda-example'}});
agenda.every('*/3 * * * *', 'delete old users');
agenda.start();

I would recommend node-cron. It allows to run tasks using Cron patterns e.g.

'* * * * * *' - runs every second
'*/5 * * * * *' - runs every 5 seconds
'10,20,30 * * * * *' - run at 10th, 20th and 30th second of every minute
'0 * * * * *' - runs every minute
'0 0 * * * *' - runs every hour (at 0 minutes and 0 seconds)

But also more complex schedules e.g.

'00 30 11 * * 1-5' - Runs every weekday (Monday through Friday) at 11:30:00 AM. It does not run on Saturday or Sunday.

Sample code: running job every 10 minutes:

var cron = require('cron');
var cronJob = cron.job("0 */10 * * * *", function(){
    // perform operation e.g. GET request http.get() etc.
    console.info('cron job completed');
}); 
cronJob.start();

You can find more examples in node-cron wiki

More on cron configuration can be found on cron wiki

I've been using that library in many projects and it does the job. I hope that will help.

I think the best ranking is

1.node-schedule

2.later

3.crontab

and the sample of node-schedule is below:

var schedule = require("node-schedule");
var rule = new schedule.RecurrenceRule();
//rule.minute = 40;
rule.second = 10;
var jj = schedule.scheduleJob(rule, function(){
    console.log("execute jj");
});

Maybe you can find the answer from node modules.