Depends on the purpose. For documents (especially those on which people work collaboratively over long periods of time) I find YYYY-MM-DD ideal. It spares the issues around day or month first when Europeans and people from the US work together, the document are easy to sort and, if it takes more than a year to complete the project (as is often the case in research) things don’t get messy.

The fourth kind is the reason I hardly ever pet any cat XD

XD fair enough ! Tbh I was just trying to see if this could be made into a joke. I’ve never had a proper taco (except maybe once, but I was drunk as hell and it was a very poorly made imitation that I wouldn’t call a taco) so I wouldn’t know what to eat it with. Please enlighten me, what kind of sauce do people put on tacos (if any)?

IMO, the end of the post’s title should be “ketchup or mayo ?”