A user reported a very strange issue - when a document with a date field is saved, it changes the value one day to the past. With every save. But only for some dates, not all. It turned out to be a mystery that goes deep into XPages and Notes/Java APIs.
This is a companion discussion topic for the original entry at https://www.pradny.com/2024/02/xpages-date-field-issue-solving-one-day.html