Use the range operator: start at line 1 and stop when you reach the date you are looking for.
As others have assumed, this assumes that the lines are in calendar order. 
www:davidj test > cat t.txt
TICKETHELP###,########,1234567###,2004,1,2,35.00###,2004-5-2 17:44:44,
+ +TICKETHELP###########1234567###2005XY356.00###,World Cup List,John 
+Ma +rck
TICKETHELP###,########,1234567###,2005,3,4,16.00###,2005-3-8 17:44:44,
+ +TICKETHELP###########1234567###2005XY356.00###,World Cup List,John 
+Ma +rck
TICKETHELP###,########,1234567###,2006,5,6,23.00###,2006-1-3 17:44:44,
+ +TICKETHELP###########1234567###2005XY356.00###,World Cup List,John 
+Ma +rck
TICKETHELP###,########,0933456###,2005,7,8,33.00###,2005-5-7 17:44:44,
+ +TICKETHELP###########1234567###2005XY356.00###,World Cup List,John 
+Ma +rck
TICKETHELP###,########,1234567###,2005,9,10,87.00###,2005-5-4 17:44:44
+ +,TICKETHELP###########1234567###2005XY356.00###,World Cup List,John
+ M +arck
TICKETHELP###,########,1984567###,2005,11,12,32.00###,2005-3-8 17:44:4
+ +4,TICKETHELP###########1234567###2005XY356.00###,World Cup List,Joh
+n +Marck
TICKETHELP###,########,1234567###,2005,13,14,67.00###,2006-5-2 17:44:4
+ +4,TICKETHELP###########1234567###2005XY356.00###,World Cup List,Joh
+n +Marck
TICKETHELP###,########,1223698###,2000,15,16,79.00###,2000-1-1 17:44:4
+ +4,TICKETHELP###########1234567###2005XY356.00###,World Cup List,Joh
+n +Marck
TICKETHELP###,########,1299n67###,2001,17,18,26.00###,2001-5-5 17:44:4
+ +4,TICKETHELP###########1234567###2005XY356.00###,World Cup List,Joh
+n +Marck

www:davidj test > cat t.pl
#!/usr/bin/perl
#
open(FILE, "<t.txt");
open(OUT, ">out.txt");
while(<FILE>) {
   print OUT $_ if 1 .. /2005-5-4/;
}
close(OUT);
close(FILE);

www:davidj test > perl t.pl
www:davidj test > cat out.txt
TICKETHELP###,########,1234567###,2004,1,2,35.00###,2004-5-2 17:44:44,
+ +TICKETHELP###########1234567###2005XY356.00###,World Cup List,John 
+Ma +rck
TICKETHELP###,########,1234567###,2005,3,4,16.00###,2005-3-8 17:44:44,
+ +TICKETHELP###########1234567###2005XY356.00###,World Cup List,John 
+Ma +rck
TICKETHELP###,########,1234567###,2006,5,6,23.00###,2006-1-3 17:44:44,
+ +TICKETHELP###########1234567###2005XY356.00###,World Cup List,John 
+Ma +rck
TICKETHELP###,########,0933456###,2005,7,8,33.00###,2005-5-7 17:44:44,
+ +TICKETHELP###########1234567###2005XY356.00###,World Cup List,John 
+Ma +rck
TICKETHELP###,########,1234567###,2005,9,10,87.00###,2005-5-4 17:44:44
+ +,TICKETHELP###########1234567###2005XY356.00###,World Cup List,John
+ M +arck
www:davidj test >

[download]
Of course the line with the date you are looking for is included, but I'm sure you can figure out how to remove it.

davidj

In reply to Re: Deleting lines prior to a date! by davidj
in thread Deleting lines prior to a date! by Anonymous Monk

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