Unable to change system date format

Dear All,

We are working with ESO 5.1.08.

Whenever a mail is sent out to suppliers, it contains US date format. We want to change it to UK date format i.e. from MM-DD-YY HH:MM am/pm to DD-Mon-YY HH:MM am/pm.

Any pointers would be highl helpful.

Regards,

Tripti