Use of the following is no longer working (apologies if I have been unable to find a deprecation). The docs (https://docs.moodle.org/dev/Writing_acceptance_tests) still refer to it:

When I set the following fields to these values:
| myDate[day] | ## yesterday ## j ## |
| myDate[month] | ## yesterday ## n ## |
| myDate[year] | ## yesterday ## Y ## |

Error:
Select option with value|text "j" not found. (Behat\Mink\Exception\ElementNotFoundException)