According to the discussion in below forum thread, if a rule based trait is being used in a segment and that has a recency of <= 1, i.e. within 1 day, then it may happen that a user qualified for the trait at 11:00 PM GMT and they will be out of the segment after an hour.
https://experienceleaguecommunities.adobe.com/t5/adobe-audience-manager-questions/recency-on-frequen...
Segment's recency and frequency settings should be evaluate qualification from the time user realized the trait, i.e 11:00 PM on day 1 to 11:00 PM on day 2.
Thanks,
Varun Kalra