diff --git a/webapp/js/dateUtils.js b/webapp/js/dateUtils.js
index 539410d..7f8686b 100644
--- a/webapp/js/dateUtils.js
+++ b/webapp/js/dateUtils.js
@@ -29,6 +29,23 @@ export function dutyOverlapsLocalDay(d, dateKey) {
   return end > dayStart && start < dayEnd;
 }
 
+/**
+ * True if duty overlaps any local day in the range [firstKey, lastKey] (inclusive).
+ * @param {object} d - Duty with start_at, end_at
+ * @param {string} firstKey - YYYY-MM-DD (first day of range)
+ * @param {string} lastKey - YYYY-MM-DD (last day of range)
+ * @returns {boolean}
+ */
+export function dutyOverlapsLocalRange(d, firstKey, lastKey) {
+  const [y1, m1, day1] = firstKey.split("-").map(Number);
+  const [y2, m2, day2] = lastKey.split("-").map(Number);
+  const rangeStart = new Date(y1, m1 - 1, day1, 0, 0, 0, 0);
+  const rangeEnd = new Date(y2, m2 - 1, day2, 23, 59, 59, 999);
+  const start = new Date(d.start_at);
+  const end = new Date(d.end_at);
+  return end > rangeStart && start < rangeEnd;
+}
+
 /** @param {Date} d - Date */
 export function firstDayOfMonth(d) {
   return new Date(d.getFullYear(), d.getMonth(), 1);
diff --git a/webapp/js/dutyList.js b/webapp/js/dutyList.js
index ea0dcb4..3777d70 100644
--- a/webapp/js/dutyList.js
+++ b/webapp/js/dutyList.js
@@ -13,7 +13,6 @@ import {
   formatTimeLocal,
   formatDateKey
 } from "./dateUtils.js";
-import { dutiesByDate } from "./calendar.js";
 
 /**
  * Build HTML for one timeline duty card: one-day "DD.MM, HH:MM – HH:MM" or multi-day.
@@ -60,8 +59,6 @@ export function dutyTimelineCardHtml(d, isCurrent) {
  * @returns {string}
  */
 export function dutyItemHtml(d, typeLabelOverride, showUntilEnd, extraClass) {
-  const startDate = new Date(d.start_at);
-  const endDate = new Date(d.end_at);
   const typeLabel =
     typeLabelOverride != null
       ? typeLabelOverride
@@ -70,25 +67,14 @@ export function dutyItemHtml(d, typeLabelOverride, showUntilEnd, extraClass) {
   if (extraClass) itemClass += " " + extraClass;
   let timeOrRange = "";
   if (showUntilEnd && d.event_type === "duty") {
-    const end =
-      String(endDate.getHours()).padStart(2, "0") +
-      ":" +
-      String(endDate.getMinutes()).padStart(2, "0");
-    timeOrRange = "до " + end;
+    timeOrRange = "до " + formatTimeLocal(d.end_at);
   } else if (d.event_type === "vacation" || d.event_type === "unavailable") {
     const startStr = formatDateKey(d.start_at);
     const endStr = formatDateKey(d.end_at);
     timeOrRange = startStr === endStr ? startStr : startStr + " – " + endStr;
   } else {
-    const start =
-      String(startDate.getHours()).padStart(2, "0") +
-      ":" +
-      String(startDate.getMinutes()).padStart(2, "0");
-    const end =
-      String(endDate.getHours()).padStart(2, "0") +
-      ":" +
-      String(endDate.getMinutes()).padStart(2, "0");
-    timeOrRange = start + " – " + end;
+    timeOrRange =
+      formatTimeLocal(d.start_at) + " – " + formatTimeLocal(d.end_at);
   }
   return (
     '<div class="' +
diff --git a/webapp/js/hints.js b/webapp/js/hints.js
index 9c4632d..2377095 100644
--- a/webapp/js/hints.js
+++ b/webapp/js/hints.js
@@ -48,6 +48,100 @@ export function positionHint(hintEl, btnRect) {
   });
 }
 
+/**
+ * Parse data-duty-items and data-date from marker; detect if any item has times.
+ * @param {HTMLElement} marker
+ * @returns {{ dutyItems: object[], hasTimes: boolean, hintDay: string }}
+ */
+function parseDutyMarkerData(marker) {
+  const dutyItemsRaw =
+    marker.getAttribute("data-duty-items") ||
+    (marker.dataset && marker.dataset.dutyItems) ||
+    "";
+  let dutyItems = [];
+  try {
+    if (dutyItemsRaw) dutyItems = JSON.parse(dutyItemsRaw);
+  } catch (e) {
+    /* ignore */
+  }
+  const hasTimes =
+    dutyItems.length > 0 &&
+    dutyItems.some((it) => {
+      const start = it.start_at != null ? it.start_at : it.startAt;
+      const end = it.end_at != null ? it.end_at : it.endAt;
+      return start || end;
+    });
+  const hintDay = marker.getAttribute("data-date") || "";
+  return { dutyItems, hasTimes, hintDay };
+}
+
+/**
+ * Get fullName from duty item (supports snake_case and camelCase).
+ * @param {object} item
+ * @returns {string}
+ */
+function getItemFullName(item) {
+  return item.full_name != null ? item.full_name : item.fullName;
+}
+
+/**
+ * Build timePrefix for one duty item in the list (shared logic for text and HTML).
+ * @param {object} item - duty item with start_at/startAt, end_at/endAt
+ * @param {number} idx - index in dutyItems
+ * @param {number} total - dutyItems.length
+ * @param {string} hintDay - YYYY-MM-DD
+ * @param {string} sep - separator after "с"/"до" (e.g. " - " for text, "\u00a0" for HTML)
+ * @returns {string}
+ */
+function buildDutyItemTimePrefix(item, idx, total, hintDay, sep) {
+  const startAt = item.start_at != null ? item.start_at : item.startAt;
+  const endAt = item.end_at != null ? item.end_at : item.endAt;
+  const endHHMM = endAt ? formatHHMM(endAt) : "";
+  const startHHMM = startAt ? formatHHMM(startAt) : "";
+  const startSameDay =
+    hintDay && startAt && localDateString(new Date(startAt)) === hintDay;
+  const endSameDay =
+    hintDay && endAt && localDateString(new Date(endAt)) === hintDay;
+  let timePrefix = "";
+  if (idx === 0) {
+    if (total === 1 && startSameDay && startHHMM) {
+      timePrefix = "с" + sep + startHHMM;
+      if (endSameDay && endHHMM && endHHMM !== startHHMM) {
+        timePrefix += " до" + sep + endHHMM;
+      }
+    } else if (endHHMM) {
+      timePrefix = "до" + sep + endHHMM;
+    }
+  } else if (idx > 0) {
+    if (startHHMM) timePrefix = "с" + sep + startHHMM;
+    if (endHHMM && endSameDay && endHHMM !== startHHMM) {
+      timePrefix += (timePrefix ? " " : "") + "до" + sep + endHHMM;
+    }
+  }
+  return timePrefix;
+}
+
+/**
+ * Get array of { timePrefix, fullName } for duty items (single source of time rules).
+ * @param {object[]} dutyItems
+ * @param {string} hintDay
+ * @param {string} timeSep - e.g. " - " for text, "\u00a0" for HTML
+ * @returns {{ timePrefix: string, fullName: string }[]}
+ */
+function getDutyMarkerRows(dutyItems, hintDay, timeSep) {
+  return dutyItems.map((item, idx) => {
+    const timePrefix = buildDutyItemTimePrefix(
+      item,
+      idx,
+      dutyItems.length,
+      hintDay,
+      timeSep
+    );
+    const fullName = getItemFullName(item);
+    return { timePrefix, fullName };
+  });
+}
+
 /**
  * Get plain text content for duty marker tooltip.
  * @param {HTMLElement} marker - .duty-marker, .unavailable-marker or .vacation-marker
@@ -59,63 +153,13 @@ export function getDutyMarkerHintContent(marker) {
   const names = marker.getAttribute("data-names") || "";
   let body;
   if (type === "duty") {
-    const dutyItemsRaw =
-      marker.getAttribute("data-duty-items") ||
-      (marker.dataset && marker.dataset.dutyItems) ||
-      "";
-    let dutyItems = [];
-    try {
-      if (dutyItemsRaw) dutyItems = JSON.parse(dutyItemsRaw);
-    } catch (e) {
-      /* ignore */
-    }
-    const hasTimes =
-      dutyItems.length > 0 &&
-      dutyItems.some((it) => {
-        const start = it.start_at != null ? it.start_at : it.startAt;
-        const end = it.end_at != null ? it.end_at : it.endAt;
-        return start || end;
-      });
+    const { dutyItems, hasTimes, hintDay } = parseDutyMarkerData(marker);
     if (dutyItems.length >= 1 && hasTimes) {
-      const hintDay = marker.getAttribute("data-date") || "";
-      body = dutyItems
-        .map((item, idx) => {
-          const startAt = item.start_at != null ? item.start_at : item.startAt;
-          const endAt = item.end_at != null ? item.end_at : item.endAt;
-          const endHHMM = endAt ? formatHHMM(endAt) : "";
-          const startHHMM = startAt ? formatHHMM(startAt) : "";
-          const startSameDay =
-            hintDay && startAt && localDateString(new Date(startAt)) === hintDay;
-          const endSameDay =
-            hintDay && endAt && localDateString(new Date(endAt)) === hintDay;
-          const fullName =
-            item.full_name != null ? item.full_name : item.fullName;
-          let timePrefix = "";
-          if (idx === 0) {
-            if (
-              dutyItems.length === 1 &&
-              startSameDay &&
-              startHHMM
-            ) {
-              timePrefix = "с - " + startHHMM;
-              if (endSameDay && endHHMM && endHHMM !== startHHMM) {
-                timePrefix += " до - " + endHHMM;
-              }
-            } else if (endHHMM) {
-              timePrefix = "до -" + endHHMM;
-            }
-          } else if (idx > 0) {
-            if (startHHMM) timePrefix = "с - " + startHHMM;
-            if (
-              endHHMM &&
-              endSameDay &&
-              endHHMM !== startHHMM
-            ) {
-              timePrefix += (timePrefix ? " " : "") + "до - " + endHHMM;
-            }
-          }
-          return timePrefix ? timePrefix + " — " + fullName : fullName;
-        })
+      const rows = getDutyMarkerRows(dutyItems, hintDay, " - ");
+      body = rows
+        .map((r) =>
+          r.timePrefix ? r.timePrefix + " — " + r.fullName : r.fullName
+        )
         .join("\n");
     } else {
       body = names;
@@ -135,65 +179,16 @@ export function getDutyMarkerHintHtml(marker) {
   const type = marker.getAttribute("data-event-type") || "duty";
   if (type !== "duty") return null;
   const names = marker.getAttribute("data-names") || "";
-  const dutyItemsRaw =
-    marker.getAttribute("data-duty-items") ||
-    (marker.dataset && marker.dataset.dutyItems) ||
-    "";
-  let dutyItems = [];
-  try {
-    if (dutyItemsRaw) dutyItems = JSON.parse(dutyItemsRaw);
-  } catch (e) {
-    /* ignore */
-  }
-  const hasTimes =
-    dutyItems.length > 0 &&
-    dutyItems.some((it) => {
-      const start = it.start_at != null ? it.start_at : it.startAt;
-      const end = it.end_at != null ? it.end_at : it.endAt;
-      return start || end;
-    });
-  const hintDay = marker.getAttribute("data-date") || "";
+  const { dutyItems, hasTimes, hintDay } = parseDutyMarkerData(marker);
   const nbsp = "\u00a0";
-  let rows;
+  let rowHtmls;
   if (dutyItems.length >= 1 && hasTimes) {
-    rows = dutyItems.map((item, idx) => {
-      const startAt = item.start_at != null ? item.start_at : item.startAt;
-      const endAt = item.end_at != null ? item.end_at : item.endAt;
-      const endHHMM = endAt ? formatHHMM(endAt) : "";
-      const startHHMM = startAt ? formatHHMM(startAt) : "";
-      const startSameDay =
-        hintDay && startAt && localDateString(new Date(startAt)) === hintDay;
-      const endSameDay =
-        hintDay && endAt && localDateString(new Date(endAt)) === hintDay;
-      const fullName =
-        item.full_name != null ? item.full_name : item.fullName;
-      let timePrefix = "";
-      if (idx === 0) {
-        if (
-          dutyItems.length === 1 &&
-          startSameDay &&
-          startHHMM
-        ) {
-          timePrefix = "с" + nbsp + startHHMM;
-          if (endSameDay && endHHMM && endHHMM !== startHHMM) {
-            timePrefix += " до" + nbsp + endHHMM;
-          }
-        } else if (endHHMM) {
-          timePrefix = "до" + nbsp + endHHMM;
-        }
-      } else if (idx > 0) {
-        if (startHHMM) timePrefix = "с" + nbsp + startHHMM;
-        if (
-          endHHMM &&
-          endSameDay &&
-          endHHMM !== startHHMM
-        ) {
-          timePrefix += (timePrefix ? " " : "") + "до" + nbsp + endHHMM;
-        }
-      }
-      const timeHtml = timePrefix ? escapeHtml(timePrefix) : "";
-      const nameHtml = escapeHtml(fullName);
-      const namePart = timePrefix ? " — " + nameHtml : nameHtml;
+    const rows = getDutyMarkerRows(dutyItems, hintDay, nbsp);
+    rowHtmls = rows.map((r) => {
+      const timeHtml = r.timePrefix ? escapeHtml(r.timePrefix) : "";
+      const namePart = r.timePrefix
+        ? " — " + escapeHtml(r.fullName)
+        : escapeHtml(r.fullName);
       return (
         '<span class="calendar-event-hint-time">' +
         timeHtml +
@@ -203,7 +198,7 @@ export function getDutyMarkerHintHtml(marker) {
       );
     });
   } else {
-    rows = (names ? names.split("\n") : []).map((fullName) => {
+    rowHtmls = (names ? names.split("\n") : []).map((fullName) => {
       const nameHtml = escapeHtml(fullName.trim());
       return (
         '<span class="calendar-event-hint-time"></span><span class="calendar-event-hint-name">' +
@@ -212,10 +207,10 @@ export function getDutyMarkerHintHtml(marker) {
       );
     });
   }
-  if (rows.length === 0) return null;
+  if (rowHtmls.length === 0) return null;
   return (
     '<div class="calendar-event-hint-title">Дежурство:</div><div class="calendar-event-hint-rows">' +
-    rows
+    rowHtmls
       .map((r) => '<div class="calendar-event-hint-row">' + r + "</div>")
       .join("") +
     "</div>"
diff --git a/webapp/js/main.js b/webapp/js/main.js
index 1272bf8..d0c6279 100644
--- a/webapp/js/main.js
+++ b/webapp/js/main.js
@@ -26,7 +26,8 @@ import {
   firstDayOfMonth,
   lastDayOfMonth,
   getMonday,
-  localDateString
+  localDateString,
+  dutyOverlapsLocalRange
 } from "./dateUtils.js";
 
 initTheme();
@@ -113,12 +114,9 @@ async function loadMonth() {
     const last = lastDayOfMonth(current);
     const firstKey = localDateString(first);
     const lastKey = localDateString(last);
-    const dutiesInMonth = duties.filter((d) => {
-      const byDateLocal = dutiesByDate([d]);
-      return Object.keys(byDateLocal).some(
-        (key) => key >= firstKey && key <= lastKey
-      );
-    });
+    const dutiesInMonth = duties.filter((d) =>
+      dutyOverlapsLocalRange(d, firstKey, lastKey)
+    );
     state.lastDutiesForList = dutiesInMonth;
     renderDutyList(dutiesInMonth);
     if (state.todayRefreshInterval) {
@@ -197,16 +195,17 @@ if (nextBtn) {
     (e) => {
       if (e.changedTouches.length === 0) return;
       if (accessDeniedEl && !accessDeniedEl.hidden) return;
-      if (prevBtn && prevBtn.disabled) return;
       const t = e.changedTouches[0];
       const deltaX = t.clientX - startX;
       const deltaY = t.clientY - startY;
       if (Math.abs(deltaX) <= SWIPE_THRESHOLD) return;
       if (Math.abs(deltaY) > Math.abs(deltaX)) return;
       if (deltaX > SWIPE_THRESHOLD) {
+        if (prevBtn && prevBtn.disabled) return;
         state.current.setMonth(state.current.getMonth() - 1);
         loadMonth();
       } else if (deltaX < -SWIPE_THRESHOLD) {
+        if (nextBtn && nextBtn.disabled) return;
         state.current.setMonth(state.current.getMonth() + 1);
         loadMonth();
       }
diff --git a/webapp/js/ui.js b/webapp/js/ui.js
index 764d22c..0129839 100644
--- a/webapp/js/ui.js
+++ b/webapp/js/ui.js
@@ -16,7 +16,7 @@ import {
 
 /**
  * Show access-denied view and hide calendar/list/loading/error.
- * @param {string} [serverDetail] - message from API 403 detail (unused; kept for callers)
+ * @param {string} [serverDetail] - message from API 403 detail (shown below main text when present)
  */
 export function showAccessDenied(serverDetail) {
   if (headerEl) headerEl.hidden = true;
@@ -25,7 +25,16 @@ export function showAccessDenied(serverDetail) {
   if (dutyListEl) dutyListEl.hidden = true;
   if (loadingEl) loadingEl.classList.add("hidden");
   if (errorEl) errorEl.hidden = true;
-  if (accessDeniedEl) accessDeniedEl.hidden = false;
+  if (accessDeniedEl) {
+    accessDeniedEl.innerHTML = "<p>Доступ запрещён.</p>";
+    if (serverDetail && serverDetail.trim()) {
+      const detail = document.createElement("p");
+      detail.className = "access-denied-detail";
+      detail.textContent = serverDetail;
+      accessDeniedEl.appendChild(detail);
+    }
+    accessDeniedEl.hidden = false;
+  }
 }
 
 /**
diff --git a/webapp/style.css b/webapp/style.css
index ffa5749..e6ea5b9 100644
--- a/webapp/style.css
+++ b/webapp/style.css
@@ -143,6 +143,7 @@ body {
 }
 
 .day {
+  position: relative;
   aspect-ratio: 1;
   display: flex;
   flex-direction: column;
@@ -175,10 +176,6 @@ body {
   border: 1px solid color-mix(in srgb, var(--today) 35%, transparent);
 }
 
-.day {
-  position: relative;
-}
-
 .info-btn {
   position: absolute;
   top: 0;
@@ -577,6 +574,12 @@ body {
   font-weight: 600;
 }
 
+.access-denied .access-denied-detail {
+  margin-top: 8px;
+  font-size: 0.9rem;
+  color: var(--muted);
+}
+
 .access-denied[hidden] {
   display: none !important;
 }