Mike Cisneros shows us an example where unexpected label values can throw off your readers:
The internet immediately latched onto the seemingly absurd collection of months portrayed in this chart. The bill, dating from June of 2019, included 13 prior months of usage from as early as August of 2016, as recently as March of 2019, and in a random order.
Soon, our non-U.S.-based friends pointed out that the dates made even less sense to them, as (of course) their convention is not to show dates in MM/YY format, but in YY/MM format.
And with this, the truth of the matter became obvious: the dates were in neither MM/YY format nor YY/MM format; they were in MM/DD format, and excluded labeling the year entirely.
Even small things can make a difference in your ability to get the message across to users.