In case of regionalization you need to link tracks from each BCS program to another. This can also be done for day templates to have a proper preparation of the days.
To allow access to the day templates of a local BCS it is important to let him keep the day templates in memory. It's no good idea to manually load the day templates by accessing it by a user.
Therefore each BCS of each site needs to have the following configuration:
Local Settings \ BroadcastServer \ Default \Memory:
KeepDayTemplatesInMemory = TRUE
Please change this because the default value would be FALSE. Linked tracks inside day templates means KeepDayTemplatesInMemory = TRUE
Please note that you have to restart BCS afterwards to load the new settings.