PL SQL Runtimes different in Shell script log

Hi,

This run times recorded in UX shell script appears peculiar to me. The PL / SQL stored procedure is called through sqlplus from UNIX shell script and then a log is created with run times recorded.

The first set has actually taken 6 Hrs but the recorded time indicates it is only 2 Hrs and 19 mins

STARTED AT: 29-NOV-08 01.36.23.671837000 PM +00:00-
ENDED AT: 29-NOV-08 02.47.08.250187000 PM +00:00
STARTED AT: 29-NOV-08 03.07.19.281072000 PM +00:00-
ENDED AT: 29-NOV-08 04.15.08.122021000 PM +00:00

Below is the second set that has actually taken 7 Hrs but the recorded time indicates it is only 1 Hr 55 mins

STARTED AT: 29-NOV-08 05.52.57.930690000 PM +00:00-
ENDED AT: 29-NOV-08 06.37.50.285460000 PM +00:00
STARTED AT: 29-NOV-08 06.59.09.941000000 PM +00:00-
ENDED AT: 29-NOV-08 09.29.55.689355000 PM +00:00

I may be missing something because it is a huge difference unless there is something that is technically noticed in the past. I know UNIX itself cannot have such anomoly but with PL / SQL and Oracle, not sure. I am sure the experts here can guide me in the right direction.

Regards,
Manjax

What's doing the recording of start/end times? Is the log in the database or in a text file?