diff --git a/packages/reservation-platform/src/utils/analytics/forecast.ts b/packages/reservation-platform/src/utils/analytics/forecast.ts
index e5ebb98..05e5576 100644
--- a/packages/reservation-platform/src/utils/analytics/forecast.ts
+++ b/packages/reservation-platform/src/utils/analytics/forecast.ts
@@ -3,21 +3,34 @@ import type { InferResultType } from "@/utils/drizzle";
 type UsagePerDay = {
 	day: number; // 0 (Sunday) to 6 (Saturday)
 	usageMinutes: number;
-	dataPoints: number;
 };
 
-function aggregateUsageByDay(jobs: InferResultType<"printJobs">[]): UsagePerDay[] {
+function aggregateUsageByDay(jobs: InferResultType<"printJobs">[]): {
+	usageData: UsagePerDay[];
+	earliestDate: Date;
+	latestDate: Date;
+} {
 	const usagePerDayMap = new Map<number, number>();
-	const usagePerDayDatapointsMap = new Map<number, number>();
+
+	let earliestDate: Date | null = null;
+	let latestDate: Date | null = null;
 
 	for (const job of jobs) {
 		let remainingDuration = job.durationInMinutes;
 		const currentStart = new Date(job.startAt);
 
+		// Update earliest and latest dates
+		if (!earliestDate || currentStart < earliestDate) {
+			earliestDate = new Date(currentStart);
+		}
+		const jobEnd = new Date(currentStart);
+		jobEnd.setMinutes(jobEnd.getMinutes() + job.durationInMinutes);
+		if (!latestDate || jobEnd > latestDate) {
+			latestDate = new Date(jobEnd);
+		}
+
 		while (remainingDuration > 0) {
 			const day = currentStart.getDay();
-			const dataPoints = usagePerDayDatapointsMap.get(day) || 0;
-			usagePerDayDatapointsMap.set(day, dataPoints + 1);
 
 			// Calculate minutes remaining in the current day
 			const minutesRemainingInDay = (24 - currentStart.getHours()) * 60 - currentStart.getMinutes();
@@ -37,17 +50,43 @@ function aggregateUsageByDay(jobs: InferResultType<"printJobs">[]): UsagePerDay[
 	const usageData: UsagePerDay[] = Array.from({ length: 7 }, (_, day) => ({
 		day,
 		usageMinutes: usagePerDayMap.get(day) || 0,
-		dataPoints: usagePerDayDatapointsMap.get(day) || 0,
 	}));
 
-	return usageData;
+	if (earliestDate === null) {
+		earliestDate = new Date();
+	}
+
+	if (latestDate === null) {
+		latestDate = new Date();
+	}
+
+	return { usageData, earliestDate: earliestDate, latestDate: latestDate };
+}
+
+function countWeekdays(startDate: Date, endDate: Date): number[] {
+	const countPerDay = Array(7).fill(0);
+	const currentDate = new Date(startDate);
+	currentDate.setHours(0, 0, 0, 0); // Ensure starting at midnight
+	endDate.setHours(0, 0, 0, 0); // Ensure ending at midnight
+
+	while (currentDate <= endDate) {
+		const day = currentDate.getDay();
+		countPerDay[day]++;
+		currentDate.setDate(currentDate.getDate() + 1);
+	}
+	return countPerDay;
 }
 
 export function forecastPrinterUsage(jobs: InferResultType<"printJobs">[]): number[] {
-	const usageData = aggregateUsageByDay(jobs);
+	const { usageData, earliestDate, latestDate } = aggregateUsageByDay(jobs);
+
+	// Count the number of times each weekday occurs in the data period
+	const weekdaysCount = countWeekdays(earliestDate, latestDate);
+
 	const forecasts: number[] = [];
 	for (const data of usageData) {
-		let usagePrediction = data.usageMinutes / data.dataPoints;
+		const dayCount = weekdaysCount[data.day];
+		let usagePrediction = data.usageMinutes / dayCount;
 		if (Number.isNaN(usagePrediction)) {
 			usagePrediction = 0;
 		}
diff --git a/packages/reservation-platform/src/utils/analytics/volume.ts b/packages/reservation-platform/src/utils/analytics/volume.ts
index 05c3eaf..a42c4e3 100644
--- a/packages/reservation-platform/src/utils/analytics/volume.ts
+++ b/packages/reservation-platform/src/utils/analytics/volume.ts
@@ -17,10 +17,13 @@ interface PrintVolumes {
 export function calculatePrintVolumes(pJobs: InferSelectModel<typeof printJobs>[]): PrintVolumes {
 	const now = new Date();
 
-	// Define time ranges
+	// Define time ranges with week starting on Monday
 	const timeRanges = {
 		today: { start: startOfDay(now), end: endOfDay(now) },
-		thisWeek: { start: startOfWeek(now), end: endOfWeek(now) },
+		thisWeek: {
+			start: startOfWeek(now, { weekStartsOn: 1 }),
+			end: endOfWeek(now, { weekStartsOn: 1 }),
+		},
 		thisMonth: { start: startOfMonth(now), end: endOfMonth(now) },
 	};