Create new event in S.Planner calendar application

[coffee2]

I have a Galaxy S3 mini (gt-i8190) with Andriod version 4.1.1. I have a problem with the standard included "S.Planner" calendar application. "Peter's calendar" is setup correctly to synchronize via Hotmail Microsoft Exchange account. I explain what I do in the "S.Planner" calendar application.
Open the "S.Planner" calendar application. Create a new event.
In the 1st field box this text is mentioned: "Bank Holidays UK". In this 1st box I open the list and I select "Peter's calendar".
In the 2nd field box I enter the title of the event.
In the 3rd field box I enter the details for this event. I save this event.
I create again a new event.
In the 1st field box this text is mentioned: "Bank Holidays UK".
Why does the 1st box again mention this text: "Bank Holidays UK"? I want that the 1st box now mentions this text as default "Peter's calendar", because I have saved the previous event in "Peter's calendar". It is very annoying that this "S.Planner" calendar application does not remember "Peter's calendar" as default calendar when entering new events.
How can I achieve that "Peter's calendar" will be default in the 1st field box always when entering new events?