export TIME_STYLE=long-iso

I found this option whilst investigating why most locales were honoured, but en_GB still gave American (backwards) dates.

I also have this, for the thousands-comma display:

  export BLOCK_SIZE="'1"

  $ ls -on i*
  -rw-rw-r-- 1 1001     1,335 2017-06-16 14:31 icon-shelters.svg
  -rw-r--r-- 1 1001 1,633,946 2016-11-07 14:50 insects.png
  -rw-r--r-- 1 1001 1,445,837 2016-11-18 10:32 ix

Block size: https://www.gnu.org/software/coreutils/manual/html_node/Bloc...

Time style: https://www.gnu.org/software/coreutils/manual/html_node/Form...