Not sure what you exactly need to achieve  but with rumba script you can  retrieve  the current date and return the day, month or year.

e.g:

 MyDate = "03/03/15"
 MyDate = "January 27, 2015"
 SysDate = Date

 MsgBox Sysdate,0,"System Date"
 MsgBox Now,0,"Now"
 
 MsgBox Day( MyDate ) & " Days"
 MsgBox Month( MyDate ) & " Months"
 MsgBox Year( MyDate ) & " Years"

The easiest way is to use the build in calendar control.

The Calendar is used to pick a date and is initially displayed on the screen as an icon. Calendar opens when you click the icon. It closes on losing focus, or when you select a date.
When you select a date in the date picker, the date is inserted on the screen at the coordinates defined by TextInsertionLocation. The format used is defined by InsertedDateFormat.
If the field occupied by Calendar contains date, the field is used by Calendar when it opens. Otherwise, Calendar uses the current date.

hope it helps

How do I even get to a script editor?

I am using Rumba version 8.0.0 SP0 Patch 0  (is this out of date)

I can find nothing about scripting.

I'm connecting to a TN3270 host. What I want to do is when I run a macro that brings up a list of open work orders, I want the macro to tab over twice to the date field and automatically fill it with the current date so I see only the open work orders for the current date.

This is how I did it in the old software we used to use:

Sendhostkeys Right("0" & DatePart("m",Now()),2)

Sendhostkeys Right("0" & DatePart("d",Now()),2)

The script editor comes in a separate installer.

Check your installation files, you should see a folder called "Micro Focus Rumba 8.0.0 Add-ons\\Micro Focus Rumba 8.0 Script Engine".

There you will find the ScriptEngine.msi.

After the  installation of  the ScriptEngine you will find the ScriptEditor in Rumba (Tools -> Edit Script)