If you are on a timezone different than UTC (i.e. the timezone offset is different than 0) then you can reproduce this issue easily like this:
- create a new page with some keyword in its content
- search for the keyword; you should get the newly created page in the results
- use the Last Modification Date facet to show only the documents that have been modified in the last X minutes
You don't get any results after applying the facet. If you add/subtract the timezone offset from the current date when applying the date facet you get the right results.
The date facet should use the timezone of the client. This means that the custom date interval that the user enters is in his local timezone.