it may help if you paste me some example lines from @aonly that exhibit the lines you are after, my test group was just pulled from a simple edgar search. This page https://www.sec.gov/Archives/edgar/data/1540531/0000905718-16-001254.txt does not exhibit lines of that type

my regex will capture anything that looks like a date, it may not be involved in the fiscal year end

Edit: for instance https://www.sec.gov/Archives/edgar/data/1084869/0001437749-16-024828.txt shows a date match on the line

<P id=PARA12 style="MARGIN-BOTTOM: 0px; TEXT-ALIGN: center; MARGIN-TOP
+: 0px; LINE-HEIGHT: 1.25"><FONT style="FONT-SIZE: 10pt; FONT-FAMILY: 
+Times New Roman, Times, serif"><B>For the quarterly period ended Dece
+mber 27, 2015</B></FONT></P>
[download]

and i repeat my concern about qr/\'\n'/ should be qr/\n/. without that change the lines can be very long and my regex has no ^ for the /m to anchor on