Provide masks DDD and DDDD to print "Yesterday", "Today" or "Tomorrow".

Readme.md

@@ -82,7 +82,9 @@ dateFormat(now, "N");
 | `d`              | Day of the month as digits; no leading zero for single-digit days.                                                                                            |
 | `dd`             | Day of the month as digits; leading zero for single-digit days.                                                                                               |
 | `ddd`            | Day of the week as a three-letter abbreviation.                                                                                                               |
+| `DDD`            | "Yesterday", "Today" or "Tomorrow" if date lies within these three days. Else fall back to ddd.                                                               |
 | `dddd`           | Day of the week as its full name.                                                                                                                             |
+| `DDDD`           | "Yesterday", "Today" or "Tomorrow" if date lies within these three days. Else fall back to dddd.                                                              |
 | `m`              | Month as digits; no leading zero for single-digit months.                                                                                                     |
 | `mm`             | Month as digits; leading zero for single-digit months.                                                                                                        |
 | `mmm`            | Month as a three-letter abbreviation.                                                                                                                         |

lib/dateformat.js

@@ -0,0 +1,255 @@
+/*
+ * Date Format 1.2.3
+ * (c) 2007-2009 Steven Levithan <stevenlevithan.com>
+ * MIT license
+ *
+ * Includes enhancements by Scott Trenda <scott.trenda.net>
+ * and Kris Kowal <cixar.com/~kris.kowal/>
+ *
+ * Accepts a date, a mask, or a date and a mask.
+ * Returns a formatted version of the given date.
+ * The date defaults to the current date/time.
+ * The mask defaults to dateFormat.masks.default.
+ */
+
+(function(global) {
+  'use strict';
+
+  var dateFormat = (function() {
+      var token = /d{1,4}|D{3,4}|m{1,4}|yy(?:yy)?|([HhMsTt])\1?|[LloSZWN]|'[^']*'|'[^']*'/g;
+      var timezone = /\b(?:[PMCEA][SDP]T|(?:Pacific|Mountain|Central|Eastern|Atlantic) (?:Standard|Daylight|Prevailing) Time|(?:GMT|UTC)(?:[-+]\d{4})?)\b/g;
+      var timezoneClip = /[^-+\dA-Z]/g;
+
+      // Regexes and supporting functions are cached through closure
+      return function (date, mask, utc, gmt) {
+
+        // You can't provide utc if you skip other args (use the 'UTC:' mask prefix)
+        if (arguments.length === 1 && kindOf(date) === 'string' && !/\d/.test(date)) {
+          mask = date;
+          date = undefined;
+        }
+
+        date = date || new Date;
+
+        if(!(date instanceof Date)) {
+          date = new Date(date);
+        }
+
+        if (isNaN(date)) {
+          throw TypeError('Invalid date');
+        }
+
+        mask = String(dateFormat.masks[mask] || mask || dateFormat.masks['default']);
+
+        // Allow setting the utc/gmt argument via the mask
+        var maskSlice = mask.slice(0, 4);
+        if (maskSlice === 'UTC:' || maskSlice === 'GMT:') {
+          mask = mask.slice(4);
+          utc = true;
+          if (maskSlice === 'GMT:') {
+            gmt = true;
+          }
+        }
+
+        var _ = utc ? 'getUTC' : 'get';
+        var d = date[_ + 'Date']();
+        var D = date[_ + 'Day']();
+        var m = date[_ + 'Month']();
+        var y = date[_ + 'FullYear']();
+        var Q = (function(){
+          var today = new Date();
+          var yesterday = new Date();
+          yesterday.setDate(yesterday.getDate() - 1);
+          var tomorrow = new Date();
+          tomorrow.setDate(tomorrow.getDate() + 1);
+          var today_d = today[_ + 'Date']();
+          var today_m = today[_ + 'Month']();
+          var today_y = today[_ + 'FullYear']();
+          var yesterday_d = yesterday[_ + 'Date']();
+          var yesterday_m = yesterday[_ + 'Month']();
+          var yesterday_y = yesterday[_ + 'FullYear']();
+          var tomorrow_d = tomorrow[_ + 'Date']();
+          var tomorrow_m = tomorrow[_ + 'Month']();
+          var tomorrow_y = tomorrow[_ + 'FullYear']();
+          var q = undefined;
+          if(today_y == y && today_m == m && today_d == d){
+            q = "Today";
+          }
+          else if(tomorrow_y == y && tomorrow_m == m && tomorrow_d == d){
+            q = "Tomorrow";
+          }
+          else if(yesterday_y == y && yesterday_m == m && yesterday_d == d){
+            q = "Yesterday";
+          }
+          return q;
+        })();
+        var H = date[_ + 'Hours']();
+        var M = date[_ + 'Minutes']();
+        var s = date[_ + 'Seconds']();
+        var L = date[_ + 'Milliseconds']();
+        var o = utc ? 0 : date.getTimezoneOffset();
+        var W = getWeek(date);
+        var N = getDayOfWeek(date);
+        var flags = {
+          d:    d,
+          dd:   pad(d),
+          ddd:  dateFormat.i18n.dayNames[D],
+          DDD:  Q || dateFormat.i18n.dayNames[D],
+          dddd: dateFormat.i18n.dayNames[D + 7],
+          DDDD: Q || dateFormat.i18n.dayNames[D + 7],
+          m:    m + 1,
+          mm:   pad(m + 1),
+          mmm:  dateFormat.i18n.monthNames[m],
+          mmmm: dateFormat.i18n.monthNames[m + 12],
+          yy:   String(y).slice(2),
+          yyyy: y,
+          h:    H % 12 || 12,
+          hh:   pad(H % 12 || 12),
+          H:    H,
+          HH:   pad(H),
+          M:    M,
+          MM:   pad(M),
+          s:    s,
+          ss:   pad(s),
+          l:    pad(L, 3),
+          L:    pad(Math.round(L / 10)),
+          t:    H < 12 ? 'a'  : 'p',
+          tt:   H < 12 ? 'am' : 'pm',
+          T:    H < 12 ? 'A'  : 'P',
+          TT:   H < 12 ? 'AM' : 'PM',
+          Z:    gmt ? 'GMT' : utc ? 'UTC' : (String(date).match(timezone) || ['']).pop().replace(timezoneClip, ''),
+          o:    (o > 0 ? '-' : '+') + pad(Math.floor(Math.abs(o) / 60) * 100 + Math.abs(o) % 60, 4),
+          S:    ['th', 'st', 'nd', 'rd'][d % 10 > 3 ? 0 : (d % 100 - d % 10 != 10) * d % 10],
+          W:    W,
+          N:    N
+        };
+
+        return mask.replace(token, function (match) {
+          if (match in flags) {
+            return flags[match];
+          }
+          return match.slice(1, match.length - 1);
+        });
+      };
+    })();
+
+  dateFormat.masks = {
+    'default':               'ddd mmm dd yyyy HH:MM:ss',
+    'shortDate':             'm/d/yy',
+    'mediumDate':            'mmm d, yyyy',
+    'longDate':              'mmmm d, yyyy',
+    'fullDate':              'dddd, mmmm d, yyyy',
+    'shortTime':             'h:MM TT',
+    'mediumTime':            'h:MM:ss TT',
+    'longTime':              'h:MM:ss TT Z',
+    'isoDate':               'yyyy-mm-dd',
+    'isoTime':               'HH:MM:ss',
+    'isoDateTime':           'yyyy-mm-dd\'T\'HH:MM:sso',
+    'isoUtcDateTime':        'UTC:yyyy-mm-dd\'T\'HH:MM:ss\'Z\'',
+    'expiresHeaderFormat':   'ddd, dd mmm yyyy HH:MM:ss Z'
+  };
+
+  // Internationalization strings
+  dateFormat.i18n = {
+    dayNames: [
+      'Sun', 'Mon', 'Tue', 'Wed', 'Thu', 'Fri', 'Sat',
+      'Sunday', 'Monday', 'Tuesday', 'Wednesday', 'Thursday', 'Friday', 'Saturday'
+    ],
+    monthNames: [
+      'Jan', 'Feb', 'Mar', 'Apr', 'May', 'Jun', 'Jul', 'Aug', 'Sep', 'Oct', 'Nov', 'Dec',
+      'January', 'February', 'March', 'April', 'May', 'June', 'July', 'August', 'September', 'October', 'November', 'December'
+    ]
+  };
+
+function pad(val, len) {
+  val = String(val);
+  len = len || 2;
+  while (val.length < len) {
+    val = '0' + val;
+  }
+  return val;
+}
+
+/**
+ * Get the ISO 8601 week number
+ * Based on comments from
+ * http://techblog.procurios.nl/k/n618/news/view/33796/14863/Calculate-ISO-8601-week-and-year-in-javascript.html
+ *
+ * @param  {Object} `date`
+ * @return {Number}
+ */
+function getWeek(date) {
+  // Remove time components of date
+  var targetThursday = new Date(date.getFullYear(), date.getMonth(), date.getDate());
+
+  // Change date to Thursday same week
+  targetThursday.setDate(targetThursday.getDate() - ((targetThursday.getDay() + 6) % 7) + 3);
+
+  // Take January 4th as it is always in week 1 (see ISO 8601)
+  var firstThursday = new Date(targetThursday.getFullYear(), 0, 4);
+
+  // Change date to Thursday same week
+  firstThursday.setDate(firstThursday.getDate() - ((firstThursday.getDay() + 6) % 7) + 3);
+
+  // Check if daylight-saving-time-switch occurred and correct for it
+  var ds = targetThursday.getTimezoneOffset() - firstThursday.getTimezoneOffset();
+  targetThursday.setHours(targetThursday.getHours() - ds);
+
+  // Number of weeks between target Thursday and first Thursday
+  var weekDiff = (targetThursday - firstThursday) / (86400000*7);
+  return 1 + Math.floor(weekDiff);
+}
+
+/**
+ * Get ISO-8601 numeric representation of the day of the week
+ * 1 (for Monday) through 7 (for Sunday)
+ * 
+ * @param  {Object} `date`
+ * @return {Number}
+ */
+function getDayOfWeek(date) {
+  var dow = date.getDay();
+  if(dow === 0) {
+    dow = 7;
+  }
+  return dow;
+}
+
+/**
+ * kind-of shortcut
+ * @param  {*} val
+ * @return {String}
+ */
+function kindOf(val) {
+  if (val === null) {
+    return 'null';
+  }
+
+  if (val === undefined) {
+    return 'undefined';
+  }
+
+  if (typeof val !== 'object') {
+    return typeof val;
+  }
+
+  if (Array.isArray(val)) {
+    return 'array';
+  }
+
+  return {}.toString.call(val)
+    .slice(8, -1).toLowerCase();
+};
+
+
+
+  if (typeof define === 'function' && define.amd) {
+    define(function () {
+      return dateFormat;
+    });
+  } else if (typeof exports === 'object') {
+    module.exports = dateFormat;
+  } else {
+    global.dateFormat = dateFormat;
+  }
+})(this);

test/test_threedays.js

@@ -0,0 +1,77 @@
+var assert = require('assert');
+
+var dateFormat = require('./../lib/dateformat');
+
+var dayNamesShort = ['Sun', 'Mon', 'Tue', 'Wed', 'Thu', 'Fri', 'Sat'];
+var dayNamesLong = ['Sunday', 'Monday', 'Tuesday', 'Wednesday', 'Thursday', 'Friday', 'Saturday'];
+var threeDays = ['Yesterday', 'Today', 'Tomorrow'];
+
+describe('threeDays', function() {
+  var date, DDD, DDDD;
+  beforeEach(function() {
+	date = new Date();
+  });
+  it('should return "Yesterday" (Today - 1 day)', function(done) {
+  	date.setDate(date.getDate() - 1);
+  	DDD = dateFormat(date, 'DDD');
+  	DDDD = dateFormat(date, 'DDDD');
+  	assert.strictEqual(DDD, "Yesterday");
+  	assert.strictEqual(DDDD, "Yesterday");
+  	done();
+  });
+  it('should return "Today" (Today)', function(done) {
+  	DDD = dateFormat(date, 'DDD');
+  	DDDD = dateFormat(date, 'DDDD');
+  	assert.strictEqual(DDD, "Today");
+  	assert.strictEqual(DDDD, "Today");
+  	done();
+  });
+  it('should return "Tomorrow" (Today + 1 day)', function(done) {
+  	date.setDate(date.getDate() + 1);
+  	DDD = dateFormat(date, 'DDD');
+  	DDDD = dateFormat(date, 'DDDD');
+  	assert.strictEqual(DDD, "Tomorrow");
+  	assert.strictEqual(DDDD, "Tomorrow");
+  	done();
+  });
+  it('should not return "Yesterday", "Today" or "Tomorrow" (Today - 2 days)', function(done) {
+  	date.setDate(date.getDate() - 2);
+  	DDD = dateFormat(date, 'DDD');
+  	DDDD = dateFormat(date, 'DDDD');
+  	assert.strictEqual(threeDays.indexOf(DDD), -1);
+  	assert.strictEqual(threeDays.indexOf(DDDD), -1);
+  	done();
+  });
+  it('should not return "Yesterday", "Today" or "Tomorrow" (Today + 2 days)', function(done) {
+  	date.setDate(date.getDate() + 2);
+  	DDD = dateFormat(date, 'DDD');
+  	DDDD = dateFormat(date, 'DDDD');
+  	assert.strictEqual(threeDays.indexOf(DDD), -1);
+  	assert.strictEqual(threeDays.indexOf(DDDD), -1);
+  	done();
+  });
+  it('should return short day name (Today - 2 days)', function(done) {
+  	date.setDate(date.getDate() - 2);
+  	DDD = dateFormat(date, 'DDD');
+  	assert.notStrictEqual(dayNamesShort.indexOf(DDD), -1);
+  	done();
+  });
+  it('should return short day name (Today + 2 days)', function(done) {
+  	date.setDate(date.getDate() + 2);
+  	DDD = dateFormat(date, 'DDD');
+  	assert.notStrictEqual(dayNamesShort.indexOf(DDD), -1);
+  	done();
+  });
+  it('should return long day name (Today - 2 days)', function(done) {
+  	date.setDate(date.getDate() - 2);
+  	DDDD = dateFormat(date, 'DDDD');
+  	assert.notStrictEqual(dayNamesLong.indexOf(DDDD), -1);
+  	done();
+  });
+  it('should return short day name (Today + 2 days)', function(done) {
+  	date.setDate(date.getDate() + 2);
+  	DDDD = dateFormat(date, 'DDDD');
+  	assert.notStrictEqual(dayNamesLong.indexOf(DDDD), -1);
+  	done();
+  });
+});