We have an inconsistency in DB schema, server, and frontend as to how 24-hour specification should be done.
For instance, table "media" has the following specification for field "period":
period varchar(100) DEFAULT '1-7,00:00-23:59' NOT NULL
At the same time, table "config" specifies the following for "work_period":
work_period varchar(100) DEFAULT '1-5,00:00-24:00' NOT NULL
The default values for periods as offered by the frontend are "1-7,00:00-23:59".
We think that 00:00-24:00 everywhere would be more correct and more intuitive.