Generate a Execution time reports using log files.

Hi Experts,

I am having a requirement, where i need to generate a report of the execution time of all the processes. All the processes generate the log files in a log directory and I can get the execution time from the log files. like below is the log file.

/home/vikas/log >ls -l CC1_ODSMH_MHPRDODS_EXTRACT_2012-04-29-03-06-42_25781.log
-rw-r--r-- 1 vikas dev 266099 Apr 29 03:17 CC1_ODSMH_MHPRDODS_EXTRACT_2012-04-29-03-06-42_25781.log

In the above entry, the RED highlights is the last modification time, and GREEN highlighted in log file name is the graph start time.
From these entries how can I find the process start and end time in the same format also the execution time ie diff between last modification time and start time.

What is your OS? Do you have GNU date?

Below is the output of uname -a

Linux prod 2.6.18-128.1.10.el5.xs5.5.0.51xen #1 SMP Wed Nov 11 08:31:24 EST 2009 x86_64