Nodejs Date Convert toRelativeTime()

Method Source Code

/*/*from   ww w  .  jav  a2  s  .  c  o m*/
 * Returns a description of this past date in relative terms.
 * Example: '3 years ago'
 */
Date.prototype.toRelativeTime = function() {
  var delta       = new Date() - this;
  var units       = null;
  var conversions = {
    millisecond: 1, // ms    -> ms
    second: 1000,   // ms    -> sec
    minute: 60,     // sec   -> min
    hour:   60,     // min   -> hour
    day:    24,     // hour  -> day
    month:  30,     // day   -> month (roughly)
    year:   12      // month -> year
  };

  for(var key in conversions) {
    if(delta < conversions[key]) {
      break;
    } else {
      units = key; // keeps track of the selected key over the iteration
      delta = delta / conversions[key];
    }
  }

  // pluralize a unit when the difference is greater than 1.
  delta = Math.floor(delta);
  if(delta !== 1) { units += "s"; }
  return [delta, units, "ago"].join(" ");
};

/*
 * Wraps up a common pattern used with this plugin whereby you take a String 
 * representation of a Date, and want back a date object.
 */
Date.fromString = function(str) {
  return new Date(Date.parse(str));
};

Related

1. toRFC2822()

   Date.prototype.toRFC2822 = function() {    
       return [
             Date.DAYS[this.getDay()] + ","
           , Date.padZero(this.getDate())
           , Date.MONTHS[this.getMonth()]
           , this.getFullYear()
           , this.getTimeString()
           , this.getTimezoneOffsetString()
       ].join(" ");
   ...
   

2. toRFC3339()

   Date.prototype.toRFC3339 = function()
     var year = this.getFullYear();
     var month = this.getMonth()+1;  
     var date = this.getDate();
     var hours = this.getHours();
     var mins = this.getMinutes();
     var secs = this.getSeconds();
     return (year+'-'+month+'-'+date+' '+hours+':'+mins+':'+secs);
   ...
   

3. toRails(name)

   Date.prototype.toRails = function(name) {
      var dateParams;
      dateParams = {};
      dateParams[name + "(1i)"] = this.getFullYear();
      dateParams[name + "(2i)"] = this.getMonth() + 1;
      dateParams[name + "(3i)"] = this.getDate();
      dateParams[name + "(4i)"] = this.getHours();
      dateParams[name + "(5i)"] = this.getMinutes();
      return dateParams;
   ...
   

4. toReadableTime()

   Date.prototype.toReadableTime = function() {
     if(this.getHours()>0) {
       return this.getHours()+"h "+this.getMinutes()+" min"
     } else {
       return this.getMinutes()+" min"
   

5. toRelativeTime( now_threshold )

   Date.prototype.toRelativeTime = function( now_threshold ) {
     var delta = new Date() - this;
     now_threshold = parseInt(now_threshold, 10);
     if (isNaN(now_threshold)) {
       now_threshold = 0;
     if (delta <= now_threshold) {
       return 'Just now';
     var units = null;
     var conversions = {
         millisecond : 1, 
         second : 1000, 
         minute : 60, 
         hour : 60, 
         day : 24, 
         month : 30, 
         year : 12
     };
     for ( var key in conversions) {
       if (delta < conversions[key]) {
         break;
       else {
         units = key; 
         delta = delta / conversions[key];
     delta = Math.floor(delta);
     if (delta !== 1) {
       units += "s";
     return [ delta, units ].join(" ");
   };
   Date.fromString = function( str ) {
     return new Date(Date.parse(str));
   };
   

6. toRelativeTime(now_threshold)

   Date.prototype.toRelativeTime = function(now_threshold) {
     var delta = new Date() - this;
     now_threshold = parseInt(now_threshold, 10);
     if (isNaN(now_threshold)) {
       now_threshold = 0;
     if (delta <= now_threshold) {
       return 'Just now';
     var units = null;
     var conversions = {
       millisecond: 1, 
       second: 1000,   
       minute: 60,     
       hour:   60,     
       day:    24,     
       month:  30,     
       year:   12      
     };
     for (var key in conversions) {
       if (delta < conversions[key]) {
         break;
       } else {
         units = key; 
         delta = delta / conversions[key];
     delta = Math.floor(delta);
     if (delta !== 1) { units += "s"; }
     return [delta, units, "ago"].join(" ");
   };
   

7. toRelativeTime(now_threshold)

   Date.prototype.toRelativeTime = function(now_threshold) {
     var delta = new Date() - this;
     now_threshold = parseInt(now_threshold, 10);
     if (isNaN(now_threshold)) {
       now_threshold = 0;
     if (Math.abs(delta) <= now_threshold) {
       return 'Just now';
     var units = null;
     var conversions = {
       millisecond: 1, 
       second: 1000,   
       minute: 60,     
       hour:   60,     
       day:    24,     
       month:  30,     
       year:   12      
     };
     for (var key in conversions) {
       if (Math.abs(delta) < conversions[key]) {
         break;
       } else {
         units = key; 
         delta = delta / conversions[key];
     delta = delta > 0 ? Math.floor(delta) : Math.ceil(delta);
     if (Math.abs(delta) !== 1) { units += "s"; }
     if (delta > 0) {
       return [delta, units, "ago"].join(" ");
     } else {
       return ["in", -delta, units].join(" ");
   };
   Date.fromString = function(str) {
     return new Date(Date.parse(str));
   };
   

8. toShortTime()

   Date.prototype.toShortTime = function() {
       return ('0' + this.getHours()).slice(-2) + ':' + ('0' + this.getMinutes()).slice(-2);
   

9. toSource()

   Date.prototype.toSource = function(){
     return '(new Date(' + this.valueOf() + '))';
   };