Ok, as part my recent "change/standardize the Oracle calendars throughout the modules" exercise I first identified all the items I would need to change: Identifying Items of the Same Type
Now I needed to update them all by setting all the items' "Navigation List for" option from "None" to "Month and Year".
To update them all I could spend a bunch of time clicking around to get to the correct page and then edit the item and then change the settings. Same applications had over 30 items I would need to change, so instead of increasing the likelihood of carpal tunnel I resorted to the classic find-and-replace skills of an text editor.
I exported the application and edited the resulting fnnn.sql file in my favorite editor (I use vim) and found that the page items I needed to correct were located in calls to wwv_flow_api.create_page_item. The date picker items had a p_display_as parameter set to "NATIVE_DATE_PICKER" and that the "Navigation List for" option was set in the parameter p_attribute_07. I quickly create a find and replace with the search string of "p_attribute_07 => 'NONE'" and a replace string of "p_attribute_07 => 'MONTH_AND_YEAR'. I executed the find and replace one by one (visually ensuring that I was replacing a p_attribute_07 line relative to a "NATIVE_DATE_PICKER" item). Saved the file and imported it back into my workspace.