Fix iso week parsing for small years

Apparently Date.UTC works only for years after 1900:

https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Date

To form an iso date, from any given year you should use an iso formatted
string. That string doesn't need 'Z' in the end ...

diff --git a/moment.js b/moment.js
index 63a6d32b4e2b5813e7da382b8e4a4c1c7b286cf1..a22e7e3299941b918cb814dcffa2429e7ab092c6 100644 (file)
--- a/moment.js
+++ b/moment.js
@@ -361,14 +361,14 @@
 
     // left zero fill a number
     // see http://jsperf.com/left-zero-filling for performance comparison
-    function leftZeroFill(number, targetLength) {
+    function leftZeroFill(number, targetLength, forceSign) {
         var output = Math.abs(number) + '',
             sign = number >= 0;
 
         while (output.length < targetLength) {
             output = '0' + output;
         }
-        return (sign ? '' : '-') + output;
+        return (sign ? (forceSign ? '+' : '') : '-') + output;
     }
 
     // helper function for _.addTime and _.subtractTime
@@ -1115,8 +1115,9 @@
         //compute day of the year from weeks and weekdays
         if (config._w && config._a[DATE] == null && config._a[MONTH] == null) {
             fixYear = function (val) {
+                var int_val = parseInt(val, 10);
                 return val ?
-                  (val.length < 3 ? (parseInt(val, 10) > 68 ? '19' + val : '20' + val) : val) :
+                  (val.length < 3 ? (int_val > 68 ? 1900 + int_val : 2000 + int_val) : int_val) :
                   (config._a[YEAR] == null ? moment().weekYear() : config._a[YEAR]);
             };
 
@@ -1481,7 +1482,10 @@
 
     //http://en.wikipedia.org/wiki/ISO_week_date#Calculating_a_date_given_the_year.2C_week_number_and_weekday
     function dayOfYearFromWeeks(year, week, weekday, firstDayOfWeekOfYear, firstDayOfWeek) {
-        var d = new Date(Date.UTC(year, 0)).getUTCDay(),
+        // The only solid way to create an iso date from year is to use
+        // a string format (Date.UTC handles only years > 1900). Don't ask why
+        // it doesn't need Z at the end.
+        var d = new Date(leftZeroFill(year, 6, true) + '-01-01').getUTCDay(),
             daysToAdd, dayOfYear;
 
         weekday = weekday != null ? weekday : firstDayOfWeek;

diff --git a/test/moment/create.js b/test/moment/create.js
index 6c3f384495c3351f2d57d6c805298aca55f2a083..a5dac42bb38037a1789c05836d7fcc77a995f069 100644 (file)
--- a/test/moment/create.js
+++ b/test/moment/create.js
@@ -733,6 +733,9 @@ exports.create = {
         //can parse other stuff too
         test.equal(moment('1999-W37-4 3:30', 'GGGG-[W]WW-E HH:mm').format('YYYY MM DD HH:mm'), '1999 09 16 03:30', "parsing weeks and hours");
 
+        // Years less than 100
+        ver('0098-06', 'GGGG-WW', "0098 02 03", "small years work", true);
+
         test.done();
     },