Use the node.js module node-schedule to do scheduled tasks

1. Installation

Command: npm install node-schedule

2. Use

There are two ways for node-schedule to do timed tasks.

2.1 Date-based Scheduling 方式

　　1. Determine the time, for example: November 21, 2017, 5:30

var schedule = require('node-schedule');
var date = new Date(2017, 11, 21, 5, 30, 0);
var j = schedule.scheduleJob(date, function(){
    console.log('The world is going to end today.');
});
j.cancel();   // Cancel the preset plan

　　2. Fixed minutes per hour, for example: 42 minutes per hour

var schedule = require('node-schedule');
var rule = new schedule.RecurrenceRule();
rule.minute = 42; 
var j = schedule.scheduleJob(rule, function(){
    console.log('The answer to life, the universe, and everything!');
});

　　3. At a certain time on certain days of the week, for example: every Thursday, Friday, Saturday, Sunday at 17:00

var rule = new schedule.RecurrenceRule();
rule.dayOfWeek = [0, new schedule.Range(4, 6)];
rule.hour = 17;
rule.minute = 0;
var j = schedule.scheduleJob(rule, function(){
    console.log('Today is recognized by Rebecca Black!');
});

　　4. Execute per second

　var rule = new schedule.RecurrenceRule();
　　var times = [];
　　for(var i=1; i<60; i++){
　　　　times.push(i);
　　}
　　rule.second = times;
　　var c=0;
　　var j = schedule.scheduleJob(rule, function(){
     　　 c++;
      　　console.log(c);
　　});

2.2 Cron-style Scheduling

The time format is as follows: 6 asterisks

1. Executed at the 42nd minute of every hour

var schedule = require('node-schedule');
 //time format is '42 * * * *' or '0 42 * * * *',
var j = schedule.scheduleJob('42 * * * *', function(){
  console.log('The answer to life, the universe, and everything!');
});

2. Execute every Friday at 12:42:00

var schedule = require('node-schedule');
 //时间格式为 ‘42 * * * 5’  或者 ‘0 42 * * * 5’，
var j = schedule.scheduleJob('42 * * * 5', function(){
  console.log('The answer to life, the universe, and everything!');
});