new timezone handling with timezoneJS.date.js

Does not work with DST yet... Maybe rewrite the js date/timehandling in php.... Status: does not work as expected!
2013-02-26 23:32:02 +00:00
parent 5af208a20f
commit 270edc7ee5
42 changed files with 20618 additions and 11 deletions
--- a/index.html
+++ b/index.html
@@ -0,0 +1,124 @@
+<!DOCTYPE html>
+<html>
+    <head>
+    <title>DST Calculator</title>
+    <script type="text/javascript">
+	
+	var myDate = 1361916817000;
+	var myTimezone = "Europe/Berlin";
+
+	function convertDateToUTC(date) { 
+		return new Date(date.getUTCFullYear(), date.getUTCMonth(), date.getUTCDate(), date.getUTCHours(), date.getUTCMinutes(), date.getUTCSeconds()); 
+    }
+	
+    function DisplayDstSwitchDates() {
+        var year = convertDateToUTC(new Date(myDate)).getYear();
+		alert(year);
+        if (year < 1000)
+            year += 1900;
+
+        var firstSwitch = 0;
+        var secondSwitch = 0;
+        var lastOffset = 99;
+
+        // Loop through every month of the current year
+        for (i = 0; i < 12; i++) {
+            // Fetch the timezone value for the month
+            var newDate = new Date(Date.UTC(year, i, 0, 0, 0, 0, 0));
+            var tz = -1 * newDate.getTimezoneOffset() / 60;
+
+            // Capture when a timzezone change occurs
+            if (tz > lastOffset)
+                firstSwitch = i-1;
+            else if (tz < lastOffset)
+                secondSwitch = i-1;
+
+            lastOffset = tz;
+        }
+
+        // Go figure out date/time occurences a minute before
+        // a DST adjustment occurs
+        var secondDstDate = FindDstSwitchDate(year, secondSwitch);
+        var firstDstDate = FindDstSwitchDate(year, firstSwitch);
+
+        if (firstDstDate == null && secondDstDate == null)
+            return 'Daylight Savings is not observed in your timezone.';
+        else
+            return 'Last minute before DST change occurs in ' +
+               year + ': ' + firstDstDate + ' and ' + secondDstDate;
+    }
+
+    function FindDstSwitchDate(year, month)
+    {
+        // Set the starting date
+        var baseDate = new Date(Date.UTC(year, month, 0, 0, 0, 0, 0));
+        var changeDay = 0;
+        var changeMinute = -1;
+        var baseOffset = -1 * baseDate.getTimezoneOffset() / 60;
+        var dstDate;
+
+        // Loop to find the exact day a timezone adjust occurs
+        for (day = 0; day < 50; day++)
+        {
+            var tmpDate = new Date(Date.UTC(year, month, day, 0, 0, 0, 0));
+            var tmpOffset = -1 * tmpDate.getTimezoneOffset() / 60;
+
+            // Check if the timezone changed from one day to the next
+            if (tmpOffset != baseOffset)
+            {
+                var minutes = 0;
+                changeDay = day;
+
+                // Back-up one day and grap the offset
+                tmpDate = new Date(Date.UTC(year, month, day-1, 0, 0, 0, 0));
+                tmpOffset = -1 * tmpDate.getTimezoneOffset() / 60;
+
+                // Count the minutes until a timezone chnage occurs
+                while (changeMinute == -1)
+                {
+                    tmpDate = new Date(Date.UTC(year, month, day-1, 0, minutes, 0, 0));
+                    tmpOffset = -1 * tmpDate.getTimezoneOffset() / 60;
+
+                    // Determine the exact minute a timezone change
+                    // occurs
+                    if (tmpOffset != baseOffset)
+                    {
+                        // Back-up a minute to get the date/time just
+                        // before a timezone change occurs
+                        tmpOffset = new Date(Date.UTC(year, month,
+                                             day-1, 0, minutes-1, 0, 0));
+                        changeMinute = minutes;
+                        break;
+                    }
+                    else
+                        minutes++;
+                }
+
+                // Add a month (for display) since JavaScript counts
+                // months from 0 to 11
+                dstDate = tmpOffset.getMonth() + 1;
+
+                // Pad the month as needed
+                if (dstDate < 10) dstDate = "0" + dstDate;
+
+                // Add the day and year
+                dstDate += '/' + tmpOffset.getDate() + '/' + year + ' ';
+ 
+                // Capture the time stamp
+                tmpDate = new Date(Date.UTC(year, month,
+                                   day-1, 0, minutes-1, 0, 0));
+                dstDate += tmpDate.toTimeString().split(' ')[0];
+                return dstDate;
+            }
+        }
+    }
+
+    </script>
+    </head>
+    <body>
+        <script type="text/javascript">
+            document.write("Current date/time: " + convertDateToUTC(new Date(myDate)) + "<br />");
+            document.write(DisplayDstSwitchDates());
+        </script>
+    </body>
+</html>