Don't mess with data date formats.
I see a ton of M/D/Y dates in Ontario businesses, since the amount of trade with the USA makes adopting their standard more convenient. My personal little protest is writing dates on forms as 13 Aug 2017, so there’s no confusion on month, and dating files with YY-MM-DD.
I once had an employer take issue with that file naming convention, and he ordered me to change it to MM-DD-YY. These are files that our sales and service people needed constantly, and need in chronological order.
Idiot Manager: “Change these dates to look like regular dates.” Me: “They sort better this way though, and the sales and service people need-” Idiot Manager: “IDGAF, CHANGE IT NOW.” Me: -.- “Yes sir.”
The change forced me to work overtime, which I recorded as time worked (and was not exempt from OT), and productivity in all other departments decreased by at least 50%. The manager gave me notice (fired me), because those orders had cost his budget an extra $4000 of OT while changing decades of dates to a stupid date format, and seriously hampered the other two departments.
During my last week, I took all of the emails we had exchanged about how changing the date format would be a bad idea, and all records of the work I had done, and sent them to the heads of the other departments, the CFO, COO, aand CEO. Just to let them know about the new date format and cascade to their teams, of course, since I wouldn’t be around anymore. Cue a flurry of miffed conversation between all of those executives.
About a week after I had left, I got a call from a very angry former manager about how I had cost him his job. Hung up on him. A couple of hours later, got a call from the COO, who conferenced in the other department heads, and they offered me that manager’s job (after I fixed the dates back). We settled on a 10% raise on that manager’s salary, and another $5,000 to fix the dates.
The CFO and COO greeted me upon returning, asking how long the reversal would take. I had them wait a moment, and ran a script that I had written the night prior that would change all the dates back in under an hour. I was lucky that they weren’t upset, and understood exactly what I had done. Especially since I pointed out that I didn’t need to hire someone else to do my old job, and we saved an entire salary by combining the two jobs.
TL;DR: Idiot manager switches date formats, loses job, I get paid just under ten grand to do a bunch of busywork and run a script to reverse that busywork, plus his job and raise. Bonus points for saving the company (well, my department) money overall.
As an addendum, we were not the IT department and so the manager did not understand what programming was or that the change could be automated.