diff --git a/src/EventModal.svelte b/src/EventModal.svelte
index 00bc046..b386cd3 100644
--- a/src/EventModal.svelte
+++ b/src/EventModal.svelte
@@ -56,7 +56,10 @@
     </span>
 
     <span>
-      {#if event.allDay}
+      {#if event.extendedProps.simAllDay}
+        <Icon name="calendar-range" class="text-primary" />
+        <span class="ms-1">{dateFormat(event.start)} ({timeFormat(event.extendedProps.realStart)}) - {dateFormat(event.end)} ({timeFormat(event.extendedProps.realEnd)})</span>
+      {:else if event.allDay}
         <Icon name="calendar-range" class="text-primary" />
         <span class="ms-1">{dateFormat(event.start)} - {dateFormat(event.end)}</span>
       {:else}
diff --git a/src/calendar.js b/src/calendar.js
index e3c0b36..c8ef67a 100644
--- a/src/calendar.js
+++ b/src/calendar.js
@@ -132,13 +132,31 @@ function fcEventFromjCalEvent(cal) {
   return function (evt) {
     const start = new Date(evt.dtstart)
     const end = new Date(evt.dtend)
+
+    const allDay = !evt.dtstart.endsWith('Z')
+
+    const duration = end - start // in ms
+    const dayMs = 24 * 3600 * 1000
+
     const fcEvent = {
       title: `${cal.short_name ?? cal.name} : ${evt.summary}`,
       start: evt.dtstart,
       end: evt.dtend,
       color: cal.color,
       textColor: invertColor(cal.color),
-      duration: end - start // in ms
+      duration: duration
+    }
+
+    if (!allDay && (duration > dayMs - 1)) {
+      fcEvent.allDay = true
+      fcEvent.simAllDay = true
+
+      fcEvent.realStart = new Date(start)
+      fcEvent.realEnd = new Date(end)
+
+      fcEvent.start = start.setUTCHours(0, 0, 0)
+      fcEvent.end = end.setUTCHours(23, 59, 59)
+      fcEvent.duration = end - start // Update the duration
     }
 
     fcEvent.calendar = cal.name