cd /usr/share/i18n/locales
cp en_AU en_JJ
vim en_JJ

Change metadata:

title      "English locale for John Elliot V"
language   "John's English"

And prefix d_fmt with:

d_fmt "<U0025><U0061><U0020>

Then:

sudo localedef -f UTF-8 -i en_JJ en_JJ.UTF-8

Then:

vim /etc/environment

add add:

LC_TIME="en_JJ.UTF-8"