Specific dates have disappeared - HELP

Help! Suddenly all the specific dates have disappeared!

So every entry where I typed “April 28, 1787,” now only reads “April 1787.”

It does that on spreadsheet view, timeline view, etc.

Cannot for the life of me figure out how that happened, or how to get it back, and can’t located any place in instructions…

Aeon Timeline has the option for you to set the maximum precision for dates of your events. It sounds like this has been changed, and that’s why you can no longer have events with day precision.
Open Timeline Settings (the cog icon) and look under the dropdown titled Maximum Precision. If you want to be able to have days, then it should say day or smaller (eg. hour, minute, second etc.), whereas it sounds like it is set to month.