Replace week notation with day.month date format; fix leap year M2-M9 DOY offset and holiday count

seth.js

@@ -68,13 +68,44 @@ function getDayOfYear(date, zone) {
   return { year, doy };
 }
 
+// Notation helpers
+// short:   D.M          e.g. "30.1"
+// medium:  D.M.YY       e.g. "30.1.26"
+// log:     DD.M.YYYY    e.g. "30.1.2026"  (DD zero-pads to 2 digits)
+// full:    YYYY.M.DD    e.g. "2026.1.30"
+
+function sethShort(sd) {
+  if (sd.type === "leapday") return "Leap Day";
+  if (sd.type === "holiday") return `H${sd.holiday}`;
+  return `${sd.day}.${sd.month}`;
+}
+
+function sethMedium(sd) {
+  if (sd.type === "leapday") return "Leap Day";
+  if (sd.type === "holiday") return `H${sd.holiday}.${String(sd.year).slice(-2)}`;
+  return `${sd.day}.${sd.month}.${String(sd.year).slice(-2)}`;
+}
+
+function sethLog(sd) {
+  if (sd.type === "leapday") return `Leap Day ${sd.year}`;
+  if (sd.type === "holiday") return `H${sd.holiday}.${sd.year}`;
+  return `${String(sd.day).padStart(2,"0")}.${sd.month}.${sd.year}`;
+}
+
+function sethFull(sd) {
+  if (sd.type === "leapday") return `${sd.year}.Leap`;
+  if (sd.type === "holiday") return `${sd.year}.H${sd.holiday}`;
+  return `${sd.year}.${sd.month}.${sd.day}`;
+}
+
+// Legacy display helpers (used by seth.html dateLine)
 function formatSethDate(sd) {
   if (sd.type === "leapday") return "Leap Day";
   if (sd.type === "holiday") {
     const total = sd.leap ? 6 : 5;
     return `Holiday ${sd.holiday} of ${total}`;
   }
-  return `Month ${sd.month}, Week ${sd.week}, Day ${sd.weekDay}`;
+  return `${sd.day}.${sd.month}  (Month ${sd.month}, Day ${sd.day})`;
 }
 
 function formatSethLong(sd) {
@@ -88,7 +119,7 @@ function formatSethLong(sd) {
     else if (isBoxingDay) note = " — Boxing Day";
     return `${sd.year} Holiday ${sd.holiday}${note}`;
   }
-  return `${sd.year} M${sd.month} W${sd.week} D${sd.weekDay}  (Month ${sd.month}, Day ${sd.day})`;
+  return `${sethLog(sd)}  (${sd.year}.${sd.month}.${sd.day})`;
 }
 
 // --- Decimal time (same as decimal page) ---