diff --git a/src/org/april/agirstatool/cli/AgirStatoolCLI.java b/src/org/april/agirstatool/cli/AgirStatoolCLI.java
index cd723ab..077e600 100644
--- a/src/org/april/agirstatool/cli/AgirStatoolCLI.java
+++ b/src/org/april/agirstatool/cli/AgirStatoolCLI.java
@@ -21,6 +21,7 @@ package org.april.agirstatool.cli;
 import java.io.File;
 import java.sql.Connection;
 import java.time.LocalDateTime;
+import java.util.Locale;
 
 import org.apache.commons.lang3.StringUtils;
 import org.apache.log4j.BasicConfigurator;
@@ -128,6 +129,9 @@ public final class AgirStatoolCLI
 				}
 			});
 
+			// Set the locale to France is required for week alignment.
+			Locale.setDefault(Locale.FRANCE);
+
 			logger.info("{} AgirStatool call: {}", LocalDateTime.now(), new StringList(args).toStringSeparatedBy(" "));
 
 			// logger.info("Single connection opened with [{}].", this.url);
diff --git a/src/org/april/agirstatool/core/AgirStatoolUtils.java b/src/org/april/agirstatool/core/AgirStatoolUtils.java
index 3cd4598..074bf89 100644
--- a/src/org/april/agirstatool/core/AgirStatoolUtils.java
+++ b/src/org/april/agirstatool/core/AgirStatoolUtils.java
@@ -23,6 +23,7 @@ import java.time.LocalDateTime;
 import java.time.ZoneOffset;
 import java.time.format.DateTimeFormatter;
 import java.util.Date;
+import java.util.Locale;
 
 import org.apache.commons.lang3.StringUtils;
 import org.apache.commons.lang3.math.NumberUtils;
@@ -43,8 +44,8 @@ public class AgirStatoolUtils
 {
 	private static Logger logger = LoggerFactory.getLogger(ProjectPage.class);
 
-	public static final DateTimeFormatter PATTERN_SHORTDATE = DateTimeFormatter.ofPattern("dd/MM/yyyy");
-	public static final DateTimeFormatter PATTERN_LONGDATE = DateTimeFormatter.ofPattern("dd/MM/yyyy hh'h'mm");
+	public static final DateTimeFormatter PATTERN_SHORTDATE = DateTimeFormatter.ofPattern("dd/MM/yyyy", Locale.FRANCE);
+	public static final DateTimeFormatter PATTERN_LONGDATE = DateTimeFormatter.ofPattern("dd/MM/yyyy hh':'mm", Locale.FRANCE);
 
 	/**
 	 * Normalise week date.
@@ -89,14 +90,14 @@ public class AgirStatoolUtils
 
 		LocalDate normalizedEnd = normaliseWeekDate(end);
 		LocalDate date = normaliseWeekDate(start);
-		int index = source.indexOf(start.format(DateTimeFormatter.ofPattern("yyyyww")));
+		int index = source.indexOf(toYearWeek(start));
 		if (index == -1)
 		{
 			index = 0;
 		}
 		while (date.isBefore(normalizedEnd) || date.isEqual(normalizedEnd))
 		{
-			String dateToken = date.format(DateTimeFormatter.ofPattern("yyyyww"));
+			String dateToken = toYearWeek(date);
 			long count;
 			if (index < source.size())
 			{
@@ -145,7 +146,7 @@ public class AgirStatoolUtils
 		long count = 0;
 		while (date.isBefore(end) || date.isEqual(end))
 		{
-			String dateToken = date.format(DateTimeFormatter.ofPattern("yyyyww"));
+			String dateToken = toYearWeek(date);
 			DateCount current = source.get(dateToken);
 			if (current != null)
 			{
@@ -398,4 +399,28 @@ public class AgirStatoolUtils
 		//
 		return result;
 	}
+
+	/**
+	 * To year week.
+	 *
+	 * @param source
+	 *            the source
+	 * @return the string
+	 */
+	public static String toYearWeek(final LocalDate source)
+	{
+		String result;
+
+		if (source == null)
+		{
+			result = null;
+		}
+		else
+		{
+			result = source.format(DateTimeFormatter.ofPattern("yyyyww", Locale.FRANCE));
+		}
+
+		//
+		return result;
+	}
 }
diff --git a/src/org/april/agirstatool/core/pages/CreatedClosedCountChartView.java b/src/org/april/agirstatool/core/pages/CreatedClosedCountChartView.java
index 805310d..ead493c 100644
--- a/src/org/april/agirstatool/core/pages/CreatedClosedCountChartView.java
+++ b/src/org/april/agirstatool/core/pages/CreatedClosedCountChartView.java
@@ -21,6 +21,7 @@ package org.april.agirstatool.core.pages;
 import java.io.IOException;
 import java.time.LocalDate;
 import java.time.format.DateTimeFormatter;
+import java.util.Locale;
 
 import org.apache.commons.codec.digest.DigestUtils;
 import org.april.agirstatool.charts.DateCountList;
@@ -229,7 +230,7 @@ public class CreatedClosedCountChartView
 			LocalDate date = AgirStatoolUtils.normaliseWeekDate(start);
 			while (date.isBefore(normalizedEnd) || date.isEqual(normalizedEnd))
 			{
-				String label = date.format(DateTimeFormatter.ofPattern("yyyy-MMM"));
+				String label = date.format(DateTimeFormatter.ofPattern("yyyy-MMM", Locale.FRANCE));
 				result.add(label);
 				date = date.plusWeeks(1);
 			}
diff --git a/src/org/april/agirstatool/core/pages/CreatedClosedDiffChartView.java b/src/org/april/agirstatool/core/pages/CreatedClosedDiffChartView.java
index 87190c6..5ade9b8 100644
--- a/src/org/april/agirstatool/core/pages/CreatedClosedDiffChartView.java
+++ b/src/org/april/agirstatool/core/pages/CreatedClosedDiffChartView.java
@@ -21,6 +21,7 @@ package org.april.agirstatool.core.pages;
 import java.io.IOException;
 import java.time.LocalDate;
 import java.time.format.DateTimeFormatter;
+import java.util.Locale;
 
 import org.apache.commons.codec.digest.DigestUtils;
 import org.april.agirstatool.charts.DateCount;
@@ -214,7 +215,7 @@ public class CreatedClosedDiffChartView
 			LocalDate date = AgirStatoolUtils.normaliseWeekDate(start);
 			while (date.isBefore(normalizedEnd) || date.isEqual(normalizedEnd))
 			{
-				String label = date.format(DateTimeFormatter.ofPattern("yyyy-MMM"));
+				String label = date.format(DateTimeFormatter.ofPattern("yyyy-MMM", Locale.FRANCE));
 				result.add(label);
 				date = date.plusWeeks(1);
 			}