grep file

i have the following shell script to grep file according to current date

#!/bin/ksh

a=0

if
a=`date +"%d"`
b=`date +"%e"`
then
ls -ltr *.log | egrep "$a|$b" | tr -s " " | cut -d " " -f6-9
else
echo "Records not found for $a $b "
fi
------------------------------------------------------------------------

but the o/p i m getting is that it it grepping some previous date files also

Dec 28 10:02 DBSyncController.log.13
Dec 28 19:27 DBSyncController.log.10
Dec 31 17:11 BETracker_Excp_FAIL.31122007171039.txt
Jan 1 16:45 BETracker_Excp_MAN_Expected.01012008164515.txt
Jan 1 16:49 BETracker_Excp_NEW_Expected.01012008164515.txt
Jan 5 23:10 DBMaint.log.1
Jan 6 14:09 fsync_results_01062008.txt
Jan 9 09:14 AMRInstallationStatusReport.log
Jan 9 10:44 mdcadedn03_080109_1043.nmon
Jan 9 10:48 TNSout
Jan 9 11:27 mdcadedn03_080109_1127.nmon
Jan 9 20:04 MissingReadsSummaryReport.log
Jan 10 01:08 ImportAdapter.MRMSPreRead.log.3
Jan 10 01:08 ImportAdapter.MRMSPreRead.log.2
Jan 10 01:08 ImportAdapter.MRMSPreRead.log.1