Booking database design with a twist I'm wanting to find a way to how I can implement a booking system that lets users put a start date on the booking and generate the end date whenever.

Lets take a house renting example. Say I wanted to book a house from a particular starting date, but I'm not sure when I'll leave, the maximum stay for users who don't put a end date is 3 days, how could I do build my database so there aren't any booking overlaps?

The current structure I have is:

booking

booking_id      | integer | not null default nextval('booking_booking_id_seq'::regclass)
houseId | integer |
user_id         | integer | not null


booking_date

 booking_date_id | integer                     | not null default nextval('booking_date_booking_date_id_seq'::regclass)
 book_from       | timestamp without time zone | not null
 book_to         | timestamp without time zone | not null
 booking_id      | integer                     |


I'm wondering whether I store an extra field in the booking entity is_stayAndLeaveWhenever

and then in the booking_date I'd just store the book_to with the book_from + 3 days (max stay without choosing leave date)

Is that a solid solution?
the maximum stay for users who don't put a end date is 3 days,


Default end date in db = 3 days. Maybe marker "tentative". Issue being - if you do not know when they move out and can not have overlap, you MUST reserve the maximum stay.

So, your solution is as good as it gets.