New Member
Do you have to get ME day/night current and SE day/night current?

or is there only day/night which covers all planes?
Correct, you need to be current in both and being current in one does not make you current in the other.
The most efficient way would be getting night current for both. That will cover the day requirement.
FAR 61.57.
With respect to recency to carry passengers, the t/o's and landings have to be done in the same "category, class and type, if required."

With respect to IFR recency, the approaches and hold have to be done just in the same "category."