https://www.duemori.it/js/dateUtil.js

1// ===================================================================
2// Author: Matt Kruse <[email protected]>
3// WWW: http://www.mattkruse.com/
4//
5// NOTICE: You may use this code for any purpose, commercial or
6// private, without any further permission from the author. You may
7// remove this notice from your final code if you wish, however it is
8// appreciated by the author if at least my web site address is kept.
9//
10// You may *NOT* re-distribute this code in any way except through its
11// use. That means, you can include it in your product, or your web
12// site, or any other form where the code is actually being used. You
13// may not put the plain javascript up on your site for download or
14// include it in your javascript libraries for download. 
15// If you wish to share this code with others, please just point them
16// to the URL instead.
17// Please DO NOT link directly to my .js files from your site. Copy
18// the files to your server and use them there. Thank you.
19// ===================================================================
20
21// HISTORY
22// ------------------------------------------------------------------
23// May 17, 2003: Fixed bug in parseDate() for dates <1970
24// March 11, 2003: Added parseDate() function
25// March 11, 2003: Added "NNN" formatting option. Doesn't match up
26//                 perfectly with SimpleDateFormat formats, but 
27//                 backwards-compatability was required.
28
29// ------------------------------------------------------------------
30// These functions use the same 'format' strings as the 
31// java.text.SimpleDateFormat class, with minor exceptions.
32// The format string consists of the following abbreviations:
33// 
34// Field        | Full Form          | Short Form
35// -------------+--------------------+-----------------------
36// Year         | yyyy (4 digits)    | yy (2 digits), y (2 or 4 digits)
37// Month        | MMM (name or abbr.)| MM (2 digits), M (1 or 2 digits)
38//              | NNN (abbr.)        |
39// Day of Month | dd (2 digits)      | d (1 or 2 digits)
40// Day of Week  | EE (name)          | E (abbr)
41// Hour (1-12)  | hh (2 digits)      | h (1 or 2 digits)
42// Hour (0-23)  | HH (2 digits)      | H (1 or 2 digits)
43// Hour (0-11)  | KK (2 digits)      | K (1 or 2 digits)
44// Hour (1-24)  | kk (2 digits)      | k (1 or 2 digits)
45// Minute       | mm (2 digits)      | m (1 or 2 digits)
46// Second       | ss (2 digits)      | s (1 or 2 digits)
47// AM/PM        | a                  |
48//
49// NOTE THE DIFFERENCE BETWEEN MM and mm! Month=MM, not mm!
50// Examples:
51//  "MMM d, y" matches: January 01, 2000
52//                      Dec 1, 1900
53//                      Nov 20, 00
54//  "M/d/yy"   matches: 01/20/00
55//                      9/2/00
56//  "MMM dd, yyyy hh:mm:ssa" matches: "January 01, 2000 12:30:45AM"
57// ------------------------------------------------------------------
58
59var MONTH_NAMES = new Array('January', 'February', 'March', 'April', 'May', 'June', 'July', 'August', 'September', 'October', 'November', 'December', 'Jan', 'Feb', 'Mar', 'Apr', 'May', 'Jun', 'Jul', 'Aug', 'Sep', 'Oct', 'Nov', 'Dec');
60var DAY_NAMES = new Array('Sunday', 'Monday', 'Tuesday', 'Wednesday', 'Thursday', 'Friday', 'Saturday', 'Sun', 'Mon', 'Tue', 'Wed', 'Thu', 'Fri', 'Sat');
61function LZ(x) { return (x < 0 || x > 9 ? "" : "0") + x }
62
63// ------------------------------------------------------------------
64// isDate ( date_string, format_string )
65// Returns true if date string matches format of format string and
66// is a valid date. Else returns false.
67// It is recommended that you trim whitespace around the value before
68// passing it to this function, as whitespace is NOT ignored!
69// ------------------------------------------------------------------
70function isDate(val, format) {
71    var date = getDateFromFormat(val, format);
72    if (date == 0) { return false; }
73    return true;
74}
75
76// -------------------------------------------------------------------
77// compareDates(date1,date1format,date2,date2format)
78//   Compare two date strings to see which is greater.
79//   Returns:
80//   1 if date1 is greater than date2

81//   0 if date2 is greater than date1 of if they are the same
82//  -1 if either of the dates is in an invalid format
83// -------------------------------------------------------------------
84function compareDates(date1, dateformat1, date2, dateformat2) {
85    var d1 = getDateFromFormat(date1, dateformat1);
86    var d2 = getDateFromFormat(date2, dateformat2);
87    if (d1 == 0 || d2 == 0) {
88        return -1;
89    }
90    else if (d1 > d2) {
91        return 1;
92    }
93    return 0;
94}
95
96// ------------------------------------------------------------------
97// formatDate (date_object, format)
98// Returns a date in the output format specified.
99// The format string uses the same abbreviations as in getDateFromFormat()
100// ------------------------------------------------------------------
101function formatDate(date, format) {
102    format = format + "";
103    var result = "";
104    var i_format = 0;
105    var c = "";
106    var token = "";
107    var y = date.getYear() + "";
108    var M = date.getMonth() + 1;
109    var d = date.getDate();
110    var E = date.getDay();
111    var H = date.getHours();
112    var m = date.getMinutes();
113    var s = date.getSeconds();
114    var yyyy, yy, MMM, MM, dd, hh, h, mm, ss, ampm, HH, H, KK, K, kk, k;
115    // Convert real date parts into formatted versions
116    var value = new Object();
117    if (y.length < 4) { y = "" + (y - 0 + 1900); }
118    value["y"] = "" + y;
119    value["yyyy"] = y;
120    value["yy"] = y.substring(2, 4);
121    value["M"] = M;
122    value["MM"] = LZ(M);
123    value["MMM"] = MONTH_NAMES[M - 1];
124    value["NNN"] = MONTH_NAMES[M + 11];
125    value["d"] = d;
126    value["dd"] = LZ(d);
127    value["E"] = DAY_NAMES[E + 7];
128    value["EE"] = DAY_NAMES[E];
129    value["H"] = H;
130    value["HH"] = LZ(H);
131    if (H == 0) { value["h"] = 12; }
132    else if (H > 12) { value["h"] = H - 12; }
133    else { value["h"] = H; }
134    value["hh"] = LZ(value["h"]);
135    if (H > 11) { value["K"] = H - 12; } else { value["K"] = H; }
136    value["k"] = H + 1;
137    value["KK"] = LZ(value["K"]);
138    value["kk"] = LZ(value["k"]);
139    if (H > 11) { value["a"] = "PM"; }
140    else { value["a"] = "AM"; }
141    value["m"] = m;
142    value["mm"] = LZ(m);
143    value["s"] = s;
144    value["ss"] = LZ(s);
145    while (i_format < format.length) {
146        c = format.charAt(i_format);
147        token = "";
148        while ((format.charAt(i_format) == c) && (i_format < format.length)) {
149            token += format.charAt(i_format++);
150        }
151        if (value[token] != null) { result = result + value[token]; }
152        else { result = result + token; }
153    }
154    return result;
155}
156
157// ------------------------------------------------------------------
158// Utility functions for parsing in getDateFromFormat()
159// ------------------------------------------------------------------
160function _isInteger(val) {
161    var digits = "1234567890";
162    for (var i = 0; i < val.length; i++) {
163        if (digits.indexOf(val.charAt(i)) == -1) { return false; }
164    }
165    return true;
166}
167function _getInt(str, i, minlength, maxlength) {
168    for (var x = maxlength; x >= minlength; x--) {
169        var token = str.substring(i, i + x);
170        if (token.length < minlength) { return null; }
171        if (_isInteger(token)) { return token; }
172    }
173    return null;
174}
175
176// ------------------------------------------------------------------
177// getDateFromFormat( date_string , format_string )
178//
179// This function takes a date string and a format string. It matches
180// If the date string matches the format string, it returns the 
181// getTime() of the date. If it does not match, it returns 0.
182// ------------------------------------------------------------------
183function getDateFromFormat(val, format) {
184    val = val + "";
185    format = format + "";
186    var i_val = 0;
187    var i_format = 0;
188    var c = "";
189    var token = "";
190    var token2 = "";
191    var x, y;
192    var now = new Date();
193    var year = now.getYear();
194    var month = now.getMonth() + 1;
195    var date = 1;
196    var hh = now.getHours();
197    var mm = now.getMinutes();
198    var ss = now.getSeconds();
199    var ampm = "";
200
201    while (i_format < format.length) {

202        // Get next token from format string
203        c = format.charAt(i_format);
204        token = "";
205        while ((format.charAt(i_format) == c) && (i_format < format.length)) {
206            token += format.charAt(i_format++);
207        }
208        // Extract contents of value based on format token
209        if (token == "yyyy" || token == "yy" || token == "y") {
210            if (token == "yyyy") { x = 4; y = 4; }
211            if (token == "yy") { x = 2; y = 2; }
212            if (token == "y") { x = 2; y = 4; }
213            year = _getInt(val, i_val, x, y);
214            if (year == null) { return 0; }
215            i_val += year.length;
216            if (year.length == 2) {
217                if (year > 70) { year = 1900 + (year - 0); }
218                else { year = 2000 + (year - 0); }
219            }
220        }
221        else if (token == "MMM" || token == "NNN") {
222            month = 0;
223            for (var i = 0; i < MONTH_NAMES.length; i++) {
224                var month_name = MONTH_NAMES[i];
225                if (val.substring(i_val, i_val + month_name.length).toLowerCase() == month_name.toLowerCase()) {
226                    if (token == "MMM" || (token == "NNN" && i > 11)) {
227                        month = i + 1;
228                        if (month > 12) { month -= 12; }
229                        i_val += month_name.length;
230                        break;
231                    }
232                }
233            }
234            if ((month < 1) || (month > 12)) { return 0; }
235        }
236        else if (token == "EE" || token == "E") {
237            for (var i = 0; i < DAY_NAMES.length; i++) {
238                var day_name = DAY_NAMES[i];
239                if (val.substring(i_val, i_val + day_name.length).toLowerCase() == day_name.toLowerCase()) {
240                    i_val += day_name.length;
241                    break;
242                }
243            }
244        }
245        else if (token == "MM" || token == "M") {
246            month = _getInt(val, i_val, token.length, 2);
247            if (month == null || (month < 1) || (month > 12)) { return 0; }
248            i_val += month.length;
249        }
250        else if (token == "dd" || token == "d") {
251            date = _getInt(val, i_val, token.length, 2);
252            if (date == null || (date < 1) || (date > 31)) { return 0; }
253            i_val += date.length;
254        }
255        else if (token == "hh" || token == "h") {
256            hh = _getInt(val, i_val, token.length, 2);
257            if (hh == null || (hh < 1) || (hh > 12)) { return 0; }
258            i_val += hh.length;
259        }
260        else if (token == "HH" || token == "H") {
261            hh = _getInt(val, i_val, token.length, 2);
262            if (hh == null || (hh < 0) || (hh > 23)) { return 0; }
263            i_val += hh.length;
264        }
265        else if (token == "KK" || token == "K") {
266            hh = _getInt(val, i_val, token.length, 2);
267            if (hh == null || (hh < 0) || (hh > 11)) { return 0; }
268            i_val += hh.length;
269        }
270        else if (token == "kk" || token == "k") {
271            hh = _getInt(val, i_val, token.length, 2);
272            if (hh == null || (hh < 1) || (hh > 24)) { return 0; }
273            i_val += hh.length; hh--;
274        }
275        else if (token == "mm" || token == "m") {
276            mm = _getInt(val, i_val, token.length, 2);
277            if (mm == null || (mm < 0) || (mm > 59)) { return 0; }
278            i_val += mm.length;
279        }
280        else if (token == "ss" || token == "s") {
281            ss = _getInt(val, i_val, token.length, 2);
282            if (ss == null || (ss < 0) || (ss > 59)) { return 0; }
283            i_val += ss.length;
284        }
285        else if (token == "a") {
286            if (val.substring(i_val, i_val + 2).toLowerCase() == "am") { ampm = "AM"; }
287            else if (val.substring(i_val, i_val + 2).toLowerCase() == "pm") { ampm = "PM"; }
288            else { return 0; }
289            i_val += 2;
290        }
291        else {
292            if (val.substring(i_val, i_val + token.length) != token) { return 0; }
293            else { i_val += token.length; }
294        }
295    }
296    // If there are any trailing characters left in the value, it doesn't match
297    if (i_val != val.length) { return 0; }
298    // Is date valid for month?
299    if (month == 2) {
300        // Check for leap year
301        if (((year % 4 == 0) && (year % 100 != 0)) || (year % 400 == 0)) { // leap year
302            if (date > 29) { return 0; }
303        }
304        else { if (date > 28) { return 0; } }
305    }
306    if ((month == 4) || (month == 6) || (month == 9) || (month == 11)) {
307        if (date > 30) { return 0; }
308    }
309    // Correct hours value
310    if (hh < 12 && ampm == "PM") { hh = hh - 0 + 12; }
311    else if (hh > 11 && ampm == "AM") { hh -= 12; }
312    var newdate = new Date(year, month - 1, date, hh, mm, ss);
313    return newdate.getTime();
314}
315
316// ------------------------------------------------------------------
317// parseDate( date_string [, prefer_euro_format] )
318//
319// This function takes a date string and tries to match it to a
320// number of possible date formats to get the value. It will try to
321// match against the following international formats, in this order:
322// y-M-d   MMM d, y   MMM d,y   y-MMM-d   d-MMM-y  MMM d
323// M/d/y   M-d-y      M.d.y     MMM-d     M/d      M-d
324// d/M/y   d-M-y      d.M.y     d-MMM     d/M      d-M
325// A second argument may be passed to instruct the method to search
326// for formats like d/M/y (european format) before M/d/y (American).
327// Returns a Date object or null if no patterns match.
328// ------------------------------------------------------------------
329function parseDate(val) {
330    var preferEuro = (arguments.length == 2) ? arguments[1] : false;
331    generalFormats = new Array('y-M-d', 'MMM d, y', 'MMM d,y', 'y-MMM-d', 'd-MMM-y', 'MMM d');
332    monthFirst = new Array('M/d/y', 'M-d-y', 'M.d.y', 'MMM-d', 'M/d', 'M-d');
333    dateFirst = new Array('d/M/y', 'd-M-y', 'd.M.y', 'd-MMM', 'd/M', 'd-M');
334    var checkList = new Array('generalFormats', preferEuro ? 'dateFirst' : 'monthFirst', preferEuro ? 'monthFirst' : 'dateFirst');
335    var d = null;
336    for (var i = 0; i < checkList.length; i++) {
337        var l = window[checkList[i]];
338        for (var j = 0; j < l.length; j++) {
339            d = getDateFromFormat(val, l[j]);
340            if (d != 0) { return new Date(d); }
341        }
342    }
343    return null;
344}