delete certain files in a folder

here are some files in a folder and which ones need to be deleted, and which ones DO NOT get deleted.

05-15-20 OPEN EM.png – DELETE
05-15-20 NDP EM.png – DELETE
05-15-20 Bumper EM.png – DELETE
05-15-20_TODAY EM.png – DELETE
OPEN.png – DO NOT DELETE
NEXTDAY.png – DO NOT DELETE
BUMP1.png – DO NOT DELETE
051520_TODAY.png – DO NOT DELETE

here is my code, the delete command does NOT work.
Any ideas.

set the_weekday to weekday of (current date) as string


if the_weekday is "Friday" then
	set current_date to (current date) + (3 * days)
else
	if the_weekday is "Saturday" then
		set current_date to (current date) + (2 * days)
	else		
		set current_date to (current date) + (1 * days)
	end if
end if



--MONTH
set Monthof to month of current_date as integer -- 3
set Monthof2 to Monthof as string -- 3
set x to count Monthof2 -- 1
if x is 1 then
	set Monthof2 to "0" & Monthof2
end if


--DAY
set dayof to day of current_date -- 18
set dayof2 to dayof as string -- 3
set y to count dayof2 -- 1
if y is 1 then
	set dayof2 to "0" & dayof
end if



--YEAR
set yearof to year of current_date -- 2020
set yearof2 to yearof as string -- 3
set yearof3 to characters 3 thru 4 of yearof2


-- EXPORT NAME
set ExportFileName to Monthof2 & dayof2 & yearof3 & "_TODAY.png" -- 051520_TODAY.png



set the_promos to "OPEN.png, NEXTDAY.png, BUMP1.png, " & ExportFileName
set delete_these to ""

tell application "Finder"
	repeat with an_item in window 1
		set x to name of an_item
		if x is not in the_promos then
			set delete_these to delete_these & return & x
		end if
	end repeat
	delete every item in delete_these -- everything works but this command
end tell

If I understand correctly you may try to edit the end of your script as :

set delete_these to {}

tell application "Finder"
	repeat with an_item in window 1
		set x to name of an_item
		if x is not in the_promos then
			set end of delete_these to x
		end if
	end repeat
	delete every item in delete_these -- everything works but this command
end tell

Yvan KOENIG running High Sierra 10.13.6 in French (VALLAURIS, France) jeudi 14 mai 2020 13:37:52

figured out a work around

tell application "Finder"
	try
		set the_EMs to select (every item in window 1 whose name contains "EM")
		delete the_EMs
		delay 0.5
	end try
	
	try
		set the_omfs to select (every item in window 1 whose name contains "omf")
		delete the_omfs
		delay 0.5
	end try
	
	try
		set the_v2cache to select (every item in window 1 whose name contains "v2cache")
		--delete the_v2cache
	end try
	
end tell