Merge pull request #2 from YunaiV/master-5.0

 Fix DataTTLKeeperTimer's startTimestamp and endTimestamp

apm-collector/apm-collector-storage/collector-storage-es-provider/src/main/java/org/apache/skywalking/apm/collector/storage/es/DataTTLKeeperTimer.java

@@ -62,13 +62,14 @@ public class DataTTLKeeperTimer {
     private void delete() {
         Calendar calendar = Calendar.getInstance();
         calendar.setTimeInMillis(System.currentTimeMillis());
-        calendar.set(Calendar.DAY_OF_MONTH, -daysBefore);
+        calendar.add(Calendar.DAY_OF_MONTH, -daysBefore);
         calendar.set(Calendar.HOUR_OF_DAY, 0);
         calendar.set(Calendar.MINUTE, 0);
         calendar.set(Calendar.SECOND, 0);
 
         long startTimestamp = calendar.getTimeInMillis();
 
+        calendar.set(Calendar.HOUR_OF_DAY, 23);
         calendar.set(Calendar.MINUTE, 59);
         calendar.set(Calendar.SECOND, 59);
         long endTimestamp = calendar.getTimeInMillis();