Function Date.parse

Create a date from a string.

• Syntax Date Date.parse(String s , [ Date rd ])
  
  This function will create a date from an input string. The function is modelled over the PHP strtotime function and the uses the GNU Date Input Formats syntax.
  
  The input string can be either absolute or relative. Accepted absolute formats are
  
  Dates:
  yyyy-mm-dd
  yy-mm-dd
  mm/dd/yyyy
  
  Time
  hh:mm
  hh:mm:ss
  hh:mm:ss.xxx (xxx are milliseconds)
  You can also append am/pm to the time. Values less than 10 does not have to be prefixed with 0 but they can.
  
  Accepted relative formats are
  
  d|w i [ago], where
  
  d is an integer optionally prepended with +/-
  i is an interval. One of: year, month, week, day, hour, minute, second
  w is a relative word. One of: last, this, next, first, third, forth...twelfth (note that 'second' is not available)
  
  A relative format can also be a single word. One of: now, today, yesterday, tomorrow or fortnight (14 days)
  
  There are some differences from the PHP implementation.
  
  1. Timezones are not supported. As you can't change the timezone on the client it makes no sense.
  2. Absolute and relative formats can not be mixed.
• Parameters

  String s

  The date input string.

  Date rd (Optional)

  A reference date. If not provided all calculations are relative to the current time.

• Return value The new date.
• Examples

  To create a date using US format for 11th of feb. 1997

  var d = Date.parse('2/11/97');

  the same date could also be created using

  var d = Date.parse('02/11/1997');

  To use the current date and set the time to 11.23pm

  var d = Date.parse('11:23pm');

  or similar with seconds and milliseconds

  var d = Date.parse('23:23:02.129');

  To set the date and the time now using ISO date format

  var d = Date.parse('1997-02-11 23:23:02.129');

  Finally you can set the date using named months

  var d = Date.parse('11 feb 1997 23:23:02.129');

  Using a relative format you can advance the year of a date with

  var d = Date.parse('next year');

  or 24 years using a number (plural s is ignored)

  var d = Date.parse('24 years');

  adding the keyword ago will negate any prefixed numbers

  var d = Date.parse('24 years ago');
  // is equal to
  var d = Date.parse('-24 years');
  

  You can also advance 2 years, 4 months and 3 minutes by

  var d = Date.parse('2 years fourth month 3 minutes');

• Download
  Download this function including dependencies
  Source

  Unless otherwise noted all code in the JSLab Standard Library is licensed as GPLv3. See http://www.gnu.org/licenses/gpl.html for the entire license.

  This function has dependencies and will not work stand-alone. Use the download button above instead of copy/paste.

  // ************************************************************************** // Copyright 2007 - 2009 Tavs Dokkedahl // Contact: http://www.jslab.dk/contact.php // // This file is part of the JSLab Standard Library (JSL) Program. // // JSL is free software; you can redistribute it and/or modify // it under the terms of the GNU General Public License as published by // the Free Software Foundation; either version 3 of the License, or // any later version. // // JSL is distributed in the hope that it will be useful, // but WITHOUT ANY WARRANTY; without even the implied warranty of // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the // GNU General Public License for more details. // // You should have received a copy of the GNU General Public License // along with this program. If not, see <http://www.gnu.org/licenses/>. // *************************************************************************** // Parse a string to a date. Modelled after the PHP function strtotime Date.parse = function(s,rd) { // If s is not specified if (!s) return new Date(); // Trim s s = s.replace(/^\s+|\s+$/g,""); // If no reference date is provided the reference is now if (!rd) rd = new Date(); // Get keywords used for relative parsing var t = ''; for(var p in Date.parse.keywords) t += p + '|'; t = t.substring(0, t.length-1); var rgx = new RegExp(t,'i'); // Determine to parse absolute or relative if (rgx.test(s)) return Date.parse.relative(s, rd); else return Date.parse.absolute(s, rd); }; // Parse absolute date Date.parse.absolute = function(s, rd) { var r = null, y = null, m = null, d = null, h = null, mi = null, se = null, ms = null; // Date format 1972-09-24, 72-9-24, 72-09-24 if (r = s.match(/^(\d{4}|\d{2})-(\d{1,2})-(\d{1,2})/)) { // Year y = r[1] * 1; // Month - JS months is zero based m = r[2] * 1 - 1; // Date d = r[3] * 1; } // US date format 9/24/72 (m/d/y) else if (r = s.match(/^(\d{1,2})\/(\d{1,2})\/(\d{4}|\d{2})/)) { // Month m = r[1] * 1 - 1; // Date d = r[2] * 1; // Year y = r[3] * 1; } // Month written litteraly // Date format 4 September 1972, 24 Sept 72, 24 Sep 72, 24-sep-72 else if (r = s.match(/^(\d{1,2})(\s*|-)([a-z]{3,})((\s+|-)(\d{4}|\d{2}))?/i)) { // Date d = r[1] * 1; // Month var rgx = new RegExp('^' + r[3],'i'); for(var i=0; i<11; i++) { if (rgx.test(Date.nameOfMonths[i])) { m = i; break; } } if (m === null) throw new Error('Date.parse: Unknown month specified litteraly'); // Year if (r[6]) y = r[6] * 1; } // Check date // Check year if (y < 100) y = y > 68 && y < 100 ? 1900 + y : 2000 + y; else if (y && (y < 1972 || y > 2068)) throw new Error('Date.parse: Year out of range. Valid input is 1972 through 2068'); // Check month if (m && (m < 0 || m > 11)) throw new Error('Date.parse: Month out of range. Valid input is 01 through 12'); // Check date - don't check for 28/29 in feb etc. Just overflow dates if (d && (d < 1 || d > 31)) throw new Error('Date.parse: Date out of range. Valid input is 01 through 31'); // Set date if (y) rd.setFullYear(y); if (m !== null) rd.setMonth(m); if (d) rd.setDate(d); // *** // Parse time // *** // Old regex used to detect timezone - contains am/pm error //if (r = s.match(/(\d{1,2})\:(\d{1,2})(?:(?:\:(\d{1,2})(?:\.(\d{1,3}))?)(?:(am|pm)?))?(?:([\+-])(\d{2})\:?(\d{2}))?/)) { if (r = s.match(/(\d{1,2})\:(\d{1,2})(?:(?:\:(\d{1,2})(?:\.(\d{1,3}))?)?(?:\s*(am|pm)?))?/)) { /* Timezone TZ sign is r[6] TZ hour is r[7] TZ minutes is r[8] It doesn't make sense to adjust timezones as the you can't change timezone with JS */ // Hour h = r[1] * 1; // If am/pm is specified if (r[5]) { if (h < 1 || h > 12) throw new Error('Date.parse: Hour out of range (using am/pm). Valid input is 1 through 12'); // If am if (r[5] == 'am') { if (h == 12) h = 0; } // If pm else { if (h != 12) h = h + 12; } } else { if (h > 24) throw new Error('Date.parse: Hour out of range. Valid input is 00 through 23'); } // Minute if (r[2]) { mi = r[2] * 1; if (mi > 59) throw new Error('Date.parse: Minute out of range. Valid input is 00 through 59'); } // Seconds if (r[3]) { se = r[3] * 1; if (se > 59) throw new Error('Date.parse: Seconds out of range. Valid input is 00 through 59'); } // Msecs if (r[4]) { // For whatever reason the multiplication becomes slightly incorrect and have to be ceiled. ms = Math.ceil(('1.' + r[4]) * 1000) - 1000; } } // Set time if (h !== null) rd.setHours(h); if (mi !== null) rd.setMinutes(mi); if (se !== null) rd.setSeconds(se); if (ms !== null) rd.setMilliseconds(ms); return rd; }; // Parse relative date Date.parse.relative = function(s,rd) { // If relative date is given as a single word - ie. now, today, tomorrow, yesterday, fortnight if (/^now|today|tomorrow|fortnight|yesterday$/.test(s)) { rd.setDate(rd.getDate() + Date.parse.keywords[s]); } else { var mod; var p = /(last|this|next|first|third|fourth|fifth|sixth|seventh|eighth|ninth|tenth|eleventh|twelfth|(?:[\+-]?\d+))\s+([a-z]+)(?:\s+(ago))?/g; while((r = p.exec(s)) != null) { // r[1] is relative number or word // r[2] is time interval // r[3] is optional 'ago' // If modifier is not a number 'ago' does not apply if (/(?:[\+-]?\d+)/.test(r[1])) mod = !r[3] ? parseInt(r[1]) : -1 * parseInt(r[1]); else mod = Date.parse.keywords[r[1]]; // Remove plural s and convert to lower case r[2] = r[2].replace(/s$/,'').toLowerCase(); // Switch on interval switch(r[2]) { case 'year': rd.setFullYear(rd.getFullYear() + mod); break; case 'month': rd.setMonth(rd.getMonth() + mod); break; case 'week': rd.setDate(rd.getDate() + mod * 7); break; case 'day': rd.setDate(rd.getDate() + mod); break; case 'hour': rd.setHours(rd.getHours() + mod); break; case 'minute': rd.setMinutes(rd.getMinutes() + mod); break; case 'second': rd.setSeconds(rd.getSeconds() + mod); break; default: // Check for weekdays var rgx = new RegExp('^' + r[2],'i'); for(var i=0; i<7; i++) { if (rgx.test(Date.nameOfDays[i])) break; } // If weekday exists if (i < 7) { var d = rd.getISODay() - 1; // If weekday is in the future if (i > d) rd.setDate(rd.getDate() + (i - d) + ((mod - 1) * 7)); else rd.setDate(rd.getDate() + (i - d) + ((mod - 1) * 7) + 7); } else throw new Error('Date.parse: Unknown keyword in input'); break; } } } return rd; }; // Valid keywords in input string Date.parse.keywords = { // Absolute. Numbers are offsets in days now: 0, today: 0, tomorrow: 1, fortnight: 14, yesterday: -1, // Relative last: -1, 'this': 1, next: 1, // Ordinal numbers first: 1, third: 3, fourth: 4, fifth: 5, sixth: 6, seventh: 7, eighth: 8, ninth: 9, tenth: 10, eleventh: 11, twelfth: 12, // Intervals second: null, minute: null, hour: null, day: null, week: null, month: null, year: null };