Vespers on Dec 24 and 31

sort out Commemoration of IV Adventus and Dom infra 8vam Nat

web/cgi-bin/DivinumOfficium/Date.pm

@@ -24,14 +24,16 @@ sub getweek {
   my $n;
 
   my $advent1 = getadvent($year);
-
+	my $christmas = date_to_ydays(25, 12, $year);
+	my $tDay = $tomorrow ? $day+1 : $day;
+
   #Advent in december
   if ($t >= $advent1) {
-    if ($t < ($advent1 + 28)) {
+    if ($t < $christmas) {
       $n = 1 + floor(($t - $advent1) / 7);
       if ($month == 11 || $day < 25) { return "Adv$n"; }
     }
-    return "Nat$day";
+    return "Nat$tDay";
   }
 
   if ($month == 1 && $day < 7) {

web/cgi-bin/horas/horascommon.pl

@@ -686,7 +686,8 @@ sub concurrence {
 				$ccomrank = 0;
 			} elsif ($rank < 2		# no 2nd Vespers of a Simplex
 				|| ($version =~ /196/ && $cwinner{Rank} =~ /Dominica/i && $rank < 5) # on any Sunday, nothing of a preceding III. cl feast
-				|| (($crank >= 6 || $cwinner =~ /01-01/) && !($rank == 2.1 || $rank == 2.99 || $rank >= 4.2 ) && $cwrank[0] !~ /Dominica|feria|in.*octava/i)  # in 1st Vespers of Duplex I. cl. only commemoration of Feria major, Dominica (major), 8va privilegiata and Duplex II./I. cl
+				|| ($crank >= 6 && !($rank == 2.1 || $rank == 2.99 || $rank >= 4.2 ) && $cwrank[0] !~ /Dominica|feria|in.*octava/i)  # in 1st Vespers of Duplex I. cl. only commemoration of Feria major, Dominica (major), 8va privilegiata and Duplex II./I. cl
+				|| ($cwinner =~ /12-25|01-01/) # on Christmas Eve and New Year's Eve, nothing of a preceding Sunday
 				|| ($crank >= 5 && !($rank == 2.1 || $rank >= 2.99) && $cwrank[0] !~ /Dominica|feria|in.*octava/i)) { # in 1st Vespers of Duplex II. cl. also commemoration of any Duplex
 			@dayname = @tomorrowname;
 			$vespera = 1;