Fix issues with daylight saving time

server/sonar-ce/src/main/java/org/sonar/ce/queue/PurgeCeActivities.java

@@ -19,10 +19,11 @@
  */
 package org.sonar.ce.queue;
 
-import java.util.Calendar;
+import java.util.Date;
 import java.util.Set;
 import org.sonar.api.Startable;
 import org.sonar.api.ce.ComputeEngineSide;
+import org.sonar.api.utils.DateUtils;
 import org.sonar.api.utils.System2;
 import org.sonar.api.utils.log.Logger;
 import org.sonar.api.utils.log.Loggers;
@@ -49,24 +50,19 @@ public class PurgeCeActivities implements Startable {
   @Override
   public void start() {
     try (DbSession dbSession = dbClient.openSession(false)) {
-      Calendar sixMonthsAgo = Calendar.getInstance();
-      long now = system2.now();
-      sixMonthsAgo.setTimeInMillis(now);
-      sixMonthsAgo.add(Calendar.DATE, -180);
+      Date sixMonthsAgo = DateUtils.addDays(new Date(system2.now()), -180);
 
       LOGGER.info("Delete the Compute Engine tasks created before {}", sixMonthsAgo.getTime());
-      Set<String> ceActivityUuids = dbClient.ceActivityDao().selectOlderThan(dbSession, sixMonthsAgo.getTimeInMillis())
+      Set<String> ceActivityUuids = dbClient.ceActivityDao().selectOlderThan(dbSession, sixMonthsAgo.getTime())
         .stream()
         .map(CeActivityDto::getUuid)
         .collect(toSet());
       dbClient.ceActivityDao().deleteByUuids(dbSession, ceActivityUuids);
 
-      Calendar fourWeeksAgo = Calendar.getInstance();
-      fourWeeksAgo.setTimeInMillis(system2.now());
-      fourWeeksAgo.add(Calendar.DATE, -28);
+      Date fourWeeksAgo = DateUtils.addDays(new Date(system2.now()), -28);
 
       LOGGER.info("Delete the Scanner contexts tasks created before {}", fourWeeksAgo.getTime());
-      Set<String> scannerContextUuids = dbClient.ceScannerContextDao().selectOlderThan(dbSession, fourWeeksAgo.getTimeInMillis());
+      Set<String> scannerContextUuids = dbClient.ceScannerContextDao().selectOlderThan(dbSession, fourWeeksAgo.getTime());
       dbClient.ceScannerContextDao().deleteByUuids(
         dbSession,
         concat(ceActivityUuids.stream(), scannerContextUuids.stream()).collect(toSet()));

server/sonar-db-dao/src/main/java/org/sonar/db/purge/PurgeConfiguration.java

@@ -25,9 +25,9 @@ import java.util.Collection;
 import java.util.Date;
 import java.util.Optional;
 import javax.annotation.CheckForNull;
-import org.apache.commons.lang.time.DateUtils;
 import org.sonar.api.config.Configuration;
 import org.sonar.api.resources.Scopes;
+import org.sonar.api.utils.DateUtils;
 import org.sonar.api.utils.System2;
 import org.sonar.core.config.PurgeConstants;