Unfortunately DBMS_UTILITY.GET_TIME is not in sync with SYSDATE. That means that when SYSDATE (internal clock of the database) switches to the next higher second, DBMS_UTILITY.GET_TIME does not "overflow" from 99 to 00 100th's of second. So you'll tipicaly get something simmilar when concatenating sysdate and DBMS_UTILITY.GET_TIME:

(hh:mi:ss-cc where cc means 100th's of second from DBMS_UTILITY.GET_TIME)
10:01:30-56
10:01:30-57
10:01:31-58
...
10:01:31-99
10:01:31-00
...
10:01:31-57
10:01:32-58

Unfortunately there is no easy way you can get SYSDATE and DBMS_UTILITY.GET_TIME in sync.