Please, don’t refer/look at any of the dates of any Post/Page or of any other Data. Those are the particular dates on which the respective posts/pages or any other data was created or updated.
The Event/s (if any), in some posts/pages may be executed on the same day on which that particular post/page might be created.
Event/s (if any), in some other posts/pages may not be executed on the same day on which those particular posts/pages might have been created. The actual execution dates of these event/s are different from the creation dates of the posts/pages hosting these events.
So, please take a note of this.