upd

src/components/Calendar.tsx

@@ -6,7 +6,7 @@ import {
   eachDayOfInterval,
   endOfMonth,
   format,
-  getDay,
+  getISODay,
   isEqual,
   isWithinInterval,
   parse,
@@ -89,7 +89,7 @@ function Calendar({ schedules, handleSelect, className }: CalendarProps) {
           <div
             key={day.toString()}
             className={classNames(
-              dayIdx === 0 && colStartClasses[getDay(day) - 1]
+              dayIdx === 0 && colStartClasses[getISODay(day) - 1]
             )}
           >
             <button
@@ -100,7 +100,7 @@ function Calendar({ schedules, handleSelect, className }: CalendarProps) {
                   (schedule) =>
                     !isWithinInterval(day, {
                       start: new Date(schedule.startDate),
-                      end: addDays(new Date(schedule.startDate), 14),
+                      end: addDays(new Date(schedule.startDate), 13),
                     })
                 )
               }

src/components/SidebarTab1.tsx

@@ -18,7 +18,7 @@ function SidebarTab1() {
     companyId,
     buildId,
   } = useSidebarTabStore();
-  const [schedules, setSchedules] = useState<any[]>();
+  const [schedules, setSchedules] = useState<any[]>([]);
 
   function handleSelectDay(day: Date) {
     setSelectedDay(day);
@@ -79,7 +79,7 @@ function SidebarTab1() {
         </div>
 
         <div className="sm:mt-8 mt-6">
-          {schedules && schedules.length > 0 ? (
+          {schedules.length > 0 ? (
             <Calendar
               schedules={schedules}
               handleSelect={(day) => handleSelectDay(day)}

src/components/SidebarTab2.tsx

@@ -5,7 +5,12 @@ import { Trans } from "react-i18next";
 import useSidebarTabStore from "../stores/useSidebarStore";
 import TimeSelector from "./TimeSelector";
 import CloseIcon from "./icons/CloseIcon";
-import { eachMinuteOfInterval, format, isAfter, parse } from "date-fns";
+import {
+  eachMinuteOfInterval,
+  format,
+  isAfter,
+  parse,
+} from "date-fns";
 import i18n from "../i18n";
 import { enUS, ru } from "date-fns/locale";
 import ky from "ky";
@@ -84,6 +89,9 @@ function SidebarTab2() {
     if (!selectedDay || !build || !scheduledSessions || !schedule) return;
 
     const step = schedule.sessionDuration + schedule.sessionBreak;
+
+    console.log("selectedDay", selectedDay);
+
     const times = eachMinuteOfInterval(
       {
         start: parse(schedule.startTime, "HH:mm", selectedDay),