No need to fuss about calendars. Just need to revisit Dr. Macdonald’s Temporal Mechanics 101.
There have been several temporal incursions since the DS9 crew did theirs - Voyager, Picard, SNW and Prodigy, not to mention the rippling effects of the Temporal Wars established in Enterprise and Discovery.
Dates and details can slip as long as the major events stay more or less the same.