date format in the output from "ls -l"

Yes, the default has changed. You can change the default with TIME_STYLE
environment variable, like this:

export TIME_STYLE=long-iso

Related tips here:
http://people.debian.org/~osamu/pub/po4a/html/ch09.en.html#_customized_display_o
f_time_and_date

nice set of tutorials for debian and discussion

hat tip
teemu likonen

http://www.debian.org/doc/manuals/debian-reference/debian-reference.en.html#_cus
tomized_display_of_time_and_date