fix unit test failing on month borders (#3494)

tests/Controller/Reporting/ProjectDateRangeControllerTest.php

@@ -51,7 +51,7 @@ class ProjectDateRangeControllerTest extends ControllerBaseTest
         $activities = $this->importFixture($activities);
 
         $timesheets = new TimesheetFixtures();
-        $timesheets->setStartDate(new \DateTime());
+        $timesheets->setStartDate(new \DateTime('first day of this month'));
         $timesheets->setAmount(50);
         $timesheets->setActivities($activities);
         $timesheets->setUser($this->getUserByRole(User::ROLE_TEAMLEAD));