Fixes #70 by correctly adjusting the time from system value to UTC ti…

…me zone

xsl/map2epubOpfImpl.xsl

@@ -244,12 +244,11 @@
     <xsl:param name="effectiveCoverGraphicUri" select="''" as="xs:string" tunnel="yes"/>
 
     <!-- Context node is the map -->
-    <!-- NOTE: the spec seems to require the "Z" (indicating a UTC time) but I don't
-               know of format-dateTime() is actually timezone aware, so this
-               construction may not be 100% correct.
-      -->
+    <xsl:variable name="utcTime" as="xs:dateTime"
+      select="adjust-dateTime-to-timezone(current-dateTime(), xs:dayTimeDuration('-PT0H'))"
+    />
     <xsl:variable name="formatted-time" as="xs:string"
-      select="format-dateTime(current-dateTime(), '[Y]-[M,2]-[D,2]T[h,2]:[m,2]:[s,2]Z')"
+      select="format-dateTime($utcTime, '[Y]-[M,2]-[D,2]T[h,2]:[m,2]:[s,2]Z')"
     />
     <!-- NOTE: For EPUB3, the <meta> element has different attributes from
          EPUB2. Instead of @name and @value, it uses @property to specify