To check the last login time, using perl

 # lsuser sankar
sankar id=40753 pgrp=itc groups=itc,staff home=/home/sankarar shell=/usr/bin/ksh gecos=SANKAR , login=true su=true rlogin=true daemon=true admin=false sugroups=ALL admgroups= tpath=nosak ttys=ALL expires=0 auth1=SYSTEM auth2=NONE umask=22 registry=files SYSTEM=compat logintimes= loginretries=0 pwdwarntime=0 account_locked=false minage=0 maxage=26 maxexpired=2 minalpha=2 minother=1 mindiff=4 maxrepeats=2 minlen=8 histexpire=0 histsize=0 pwdchecks= dictionlist=/etc/security/aixpert/dictionary/English default_roles= fsize=-1 cpu=-1 data=262144 stack=65536 core=2097151 rss=65536 nofiles=2000 time_last_login=1332327025 time_last_unsuccessful_login=1329801313 tty_last_login=/dev/pts/0 tty_last_unsuccessful_login=ssh host_last_login=198.200.189.87 host_last_unsuccessful_login=18.213.208.27 unsuccessful_login_count=0 roles=



 time_last_login=1332327025


server1:/root #  perl -le 'print scalar localtime 1332327025'
Wed Mar 21 03:50:25 2012


Note:
You can verify the same timestamp using the last | grep sankar command.
However, if the user hasn’t logged into the server for several years, the last command might not display any information — because the login history is retained only for a few months and is rotated periodically.