ABCpdf: How to run javascript after PDF-File is opened?

I have a component which generates PDF-File using ABCpdf. In that PDF-File I need a “DateTime Picker” field.
There are JavaScript functions which can be used for this purpose: AFDate_Format, AFDate_FormatEx (ABCpdf Documentation)

Thus, it can be achieved with simple JavaScript Code

getField("MyField").setAction("Format","AFDate_Format(6)");
getField("MyField").setAction("Keystroke", "AFDate_Format(6)");

I know how to add JavaScript events on fields in PDF-File (e.g. on mouse click). And it works. DateTime picker control is applied to the field when I click that control in a PDF-File.

But I need to apply DateTime picker control when PDF-File is opened.

According to PDF ISO (page 109) there is ‘JavaScript Dictionary’ which can be used for this, but it is not clear hot to add it using ABCPdf

How can I execute JavaScript code when PDF-File is loaded?