dateDiff(...) -> add(...)

src/main/java/cokr/xit/base/syslog/web/LoggingController.java

@@ -59,7 +59,7 @@ public class LoggingController extends AbstractController {
 			req.setToDate(toDate.replace("-", ""));
 
 			if (isEmpty(fromDate)) {
-				fromDate = DataFormat.yyyy_mm_dd(dateDiff(date, -30));
+				fromDate = DataFormat.yyyy_mm_dd(add(date, -30));
 				req.setFromDate(fromDate.replace("-", ""));
 			}
 		}