The action: YYYY-MM-DD is the only correct way to write a date in a filename.

The long-form: Okay, so that’s not completely true, but in the realm of filenames at least, I have to talk to you about our friend and saviour ISO-8601.

Do you want all the presentations held on the 1st of any month and year to appear first in your folder? Or the files from May 1 2015, then May 1 2016, before May 2 2015 etc.? Or are you a normal human being and want to see them in chronological order?

If so, you are in for a lifetime of joy and peace if you start with the largest time-unit and end with the smallest – for example 2015-11-22

Fine, this isn’t the leadership tip that will make you into a MBA-case study, but it might slow your descent into insanity.

For more (of course you want more), see R-guru Jenny Bryan’s excellent video on filenaming.