Grep in a log file within a time range (hour)

Hi, im trying to write a grep script that returns me the last inputs added in the last hour in the log file. Literally i have nothing yet but:

grep 'Line im looking for' LOGFILE.log | tail -1

this only gives me the last input, but no necessarily from the last hour.

Help Please.

Unless you post more details, e.g. of the input file and the pattern you are looking for, it will be difficult to help.

Ok sorry...

grep 'Process BNKEL LOAD LOTS' EJELOG02092013.log | tail -1

this gives me :

Mon Sep 2 15:21:06 2013 - Process Ended BNKEL LOAD LOTS <= 50 TRXS

but i would like to get the inputs from one hour ago, since the log file contains much more info about other processes and sometimes the one im monitoring tends to fail.

If your system allows for date -d "-1hour" , try

awk -v T="$(date +"%H:%M" -d "-1hour")" 'substr ($4,1,5)>T && /Process BNKEL/' 

No, im sorry it doesnt. "AIX 5.2". Any other suggestion?

thanks in advance.