diff --git a/app/features/tournament-organization/TournamentOrganizationRepository.server.ts b/app/features/tournament-organization/TournamentOrganizationRepository.server.ts
index 656458d6f..77ab883cb 100644
--- a/app/features/tournament-organization/TournamentOrganizationRepository.server.ts
+++ b/app/features/tournament-organization/TournamentOrganizationRepository.server.ts
@@ -234,8 +234,12 @@ export async function findEventsByMonth({
 	year,
 	organizationId,
 }: FindEventsByMonthArgs) {
-	const firstDayOfTheMonth = new Date(year, month, 1);
-	const lastDayOfTheMonth = new Date(year, month + 1, 0);
+	const firstDayOfTheMonth = new Date(Date.UTC(year, month, 1));
+	const lastDayOfTheMonth = new Date(Date.UTC(year, month + 1, 0));
+
+	// a bit of margin for timezones, filtered in the frontend code
+	firstDayOfTheMonth.setUTCDate(firstDayOfTheMonth.getUTCDate() - 1);
+	lastDayOfTheMonth.setUTCDate(lastDayOfTheMonth.getUTCDate() + 1);
 
 	const events = await findEventsBaseQuery(organizationId)
 		.where(
diff --git a/app/features/tournament-organization/components/EventCalendar.tsx b/app/features/tournament-organization/components/EventCalendar.tsx
index 45fba91ac..e6bf751b9 100644
--- a/app/features/tournament-organization/components/EventCalendar.tsx
+++ b/app/features/tournament-organization/components/EventCalendar.tsx
@@ -35,12 +35,15 @@ export function EventCalendar({
 					</div>
 				))}
 				{dates.map((date, i) => {
-					const daysEvents = events.filter(
-						(event) =>
+					const daysEvents = events.filter((event) => {
+						const startTimeDate = databaseTimestampToDate(event.startTime);
+
+						return (
 							isMounted &&
-							databaseTimestampToDate(event.startTime).getDate() ===
-								date?.getDate(),
-					);
+							startTimeDate.getDate() === date?.getDate() &&
+							startTimeDate.getMonth() === date.getMonth()
+						);
+					});
 
 					return (
 						<EventCalendarCell
@@ -75,7 +78,7 @@ function EventCalendarCell({
 					date?.getFullYear() === new Date().getFullYear(),
 			})}
 		>
-			<div className="org__calendar__day__date">{date?.getDate()}</div>
+			<div className="org__calendar__day__date">{date?.getUTCDate()}</div>
 			{events.length === 1 ? (
 				<img
 					className="org__calendar__day__logo"
@@ -98,7 +101,7 @@ const monthYearSearchParams = ({ month, year }: MonthYear) =>
 		["year", String(year)],
 	]).toString();
 function MonthSelector({ month, year }: { month: number; year: number }) {
-	const date = new Date(Date.UTC(year, month, 1));
+	const date = new Date(Date.UTC(year, month, 15));
 
 	return (
 		<div className="org__calendar__month-selector">
diff --git a/app/utils/dates.ts b/app/utils/dates.ts
index 44a0c06e2..479938a7f 100644
--- a/app/utils/dates.ts
+++ b/app/utils/dates.ts
@@ -142,7 +142,7 @@ export function dateToYYYYMMDD(date: Date) {
 // same as datesOfMonth but contains null at the start to start with monday
 export function nullPaddedDatesOfMonth({ month, year }: MonthYear) {
 	const dates = datesOfMonth({ month, year });
-	const firstDay = dates[0].getDay();
+	const firstDay = dates[0].getUTCDate();
 	const nulls = Array.from(
 		{ length: firstDay === 0 ? 6 : firstDay - 1 },
 		() => null,
@@ -153,9 +153,9 @@ export function nullPaddedDatesOfMonth({ month, year }: MonthYear) {
 function datesOfMonth({ month, year }: MonthYear) {
 	const dates = [];
 	const date = new Date(Date.UTC(year, month, 1));
-	while (date.getMonth() === month) {
+	while (date.getUTCMonth() === month) {
 		dates.push(new Date(date));
-		date.setDate(date.getDate() + 1);
+		date.setUTCDate(date.getUTCDate() + 1);
 	}
 	return dates;
 }