Years ago I started writing date in YYYY-MM-DD. Seems to make the most sense for filing, be it files or folders on the computer, or papers in real life. Very simple, work from MSB to LSB.
I still marvel over the fact that while measuring distance and volume can be metric, time isn't. The second may be the base unit in metric but it's still 60 minutes to the hour, 24 to the day, 364 to the year. 7 days to a week and 30-ish days to the month. And then it gets beat up during leap years and other times of adjustment. Even metric users have to put up non-base 10 math when it comes to time. Yet the most common complaint about non-metric from metric users is... how do you remember all the different numbers if they aren't all related by factors of 10? but they manage to figure out the time of day and day of the year all the same.