inconsistent ls command display at the command prompt & running as a cron job

Sir,
I using the following commands in a file (part of a bigger script):
#!/bin/bash
cd /opt/oracle/bin
ls -lt | tail -1 | awk '{print $6}' >> /tmp/ramb.out

If I run this from the command prompt the result is:

                   2007-05-16

if I run it as a cron job then I get:

                   May

In both cases I need to get:

                   2007-05-16

Can any help with this?

Thanks in advance.

Which OS you are using. I tried the same command in AIX

ls -lt | tail -1 | awk '{print $6}'

and I got 'Jul' as response

We are using suse enterprize 9
Linux 2.6.5-7.283-smp #1 SMP Wed Nov 29 16:55:53 UTC 2006 x86_64 x86_64 x86_64 GNU/Linu

I am not sure..

try executing the command with full path

/bin/ls -lt | tail -1 | awk '{print $6}' >> /tmp/ramb.out

/bin/ls -lt --time-style=locale | ...

Cheers,
ZB

Thanks for all the suggestions and a solution.

time-style= long-iso or time-style=+%Y-%m-%d will do us nicely.

Once again thanks.