How to change default date format?

Hi All,

I've lot of date fields in my postgres tables. When ever I run a query on
date fields, the date is retrieved in
"yyyy-mm-dd" format. Every time, I've to use to_char function to convert
those fields into string. Is there is any server setting to change the
default date retrieval format into dd/mm/yyyy? Please let me know, if  there
is any way. It will be really helpful for me.

Thanks & Regards
Jaisankar