Merge pull request #7 from Edirom/issue-6

add tests for date:rfc822 and improve compliance, closes #6

testing/date-tests.xqm

@@ -35,4 +35,13 @@ declare
     let $dateElement := <tei:date from="{$date1}" to="{$date2}"/>
     return
         date:getOneNormalizedDate($dateElement, $latest)
-};
\ No newline at end of file
+};
+
+declare 
+    %test:args("2002-10-02T15:00:00.040+02:00")     %test:assertEquals("Wed, 02 Oct 2002 15:00:00 +0200")
+    %test:args("2004-02-29T23:00:00.98077-09:00")   %test:assertEquals("Sun, 29 Feb 2004 23:00:00 -0900")
+    %test:args("1969-01-12T15:00:00")               %test:assertEquals("Sun, 12 Jan 1969 15:00:00 +0000")
+    %test:args("1969-01-12T15:00:00Z")              %test:assertEquals("Sun, 12 Jan 1969 15:00:00 +0000")
+    function dt:test-rfc822($dateTime as xs:dateTime) as xs:string {
+        date:rfc822($dateTime)
+};

xquery/date.xqm

@@ -251,10 +251,13 @@ declare function date:gregorian2julian($date as xs:date) as xs:date? {
 declare function date:rfc822($dateTime as xs:dateTime) as xs:string {
     let $year := year-from-date($dateTime)
     let $month := substring(format-date($dateTime,'[MNn]'), 1, 3)
-    let $day := day-from-date($dateTime)
+    let $day := functx:pad-integer-to-length(day-from-date($dateTime), 2)
     let $day.string := substring(format-date($dateTime,'[F]'), 1, 3)
     let $time := format-time($dateTime,"[H]:[m]:[s]")
-    let $timezone := translate(format-date($dateTime, '[Z]'), ':', '')
+    let $timezone := 
+        if(exists(timezone-from-dateTime($dateTime)))
+        then translate(format-date($dateTime, '[Z]'), ':', '')
+        else '+0000'
     return (
         $day.string ||', '|| $day || ' ' || $month || ' ' || $year || ' ' || $time || ' ' || $timezone
     )