time

DD/MM/YY lists smallest to largest unit.

MM/DD/YY lists smallest to largest potential number.
(1 to 12/1 to 31/- to + infinity)

Time of day is where it gets odd.
HR:MIN:SEC
Largest to smallest unit.
1-24:1-60:1-60
Small to larger to same potential number.

If we want to stay consistent, we should go with largest to smallest unit: YY/MM/DD HR:MIN:SEC
This is also the best format for categorization and filenames and such, as all files will stay in perfect chronological order with no change of getting mixed up.

So, basically, MM/DD/YY and DD/MM/YY are equally ridiculous, and YY/MM/DD is the objectively best system.