diff --git a/src/components/Calendar.tsx b/src/components/Calendar.tsx
index ee859c2..4f6510a 100644
--- a/src/components/Calendar.tsx
+++ b/src/components/Calendar.tsx
@@ -189,7 +189,7 @@ const CalendarCourses = ({ courses: day }: { courses: WeekCourses }) => {
 							gridRowStart: getGridRow(time.time.start),
 							gridRowEnd: getGridRow(time.time.end),
 							height: calcHoursDuration(time.time) * 6 + 'rem',
-							zIndex: 10 - j, // TODO: Remove zIndex after implementing course conflicts #5
+							zIndex: j, // TODO: Remove zIndex after implementing course conflicts #5
 						}}
 					>
 						{time.courses.map((course) => (
diff --git a/src/helpers/calendar.ts b/src/helpers/calendar.ts
index b94645e..76179df 100644
--- a/src/helpers/calendar.ts
+++ b/src/helpers/calendar.ts
@@ -99,7 +99,7 @@ export const getWeekCourses = (
 
 	// TODO: Remove this sorting after implementing course conflicts #5
 	courses.forEach((dayCourses) => {
-		// Sort by duration (shortest first) and start time (latest first)
+		// Sort by duration (longest first) and start time (earliest first)
 		dayCourses.sort((a, b) => {
 			const aStart = timeToDayjs(a.time.start);
 			const aEnd = timeToDayjs(a.time.end);
@@ -110,12 +110,12 @@ export const getWeekCourses = (
 			const bDuration = bEnd.diff(bStart, 'minute');
 
 			if (aDuration === bDuration) {
-				if (aStart.isBefore(bStart)) return 1;
-				if (aStart.isAfter(bStart)) return -1;
+				if (aStart.isBefore(bStart)) return -1;
+				if (aStart.isAfter(bStart)) return 1;
 				return 0;
 			}
 
-			return aDuration - bDuration;
+			return bDuration - aDuration;
 		});
 	});