Removing from the ends is most efficient:

splice(@dn, 0, 3, ());
pop(@dn);
[download]

But unless you have a huge array, you might want the more readable:

@dn = @dn[3..$#dn-1];
[download]

I know it's a sad idictment on the capabilities of some clients with which I've worked, but a large number of them would prefer the former since they wouldn't even have thought of the latter (including me;-) - but unlike them (who would consider it to be obfuscated &/or voodoo), I do understand (and yes, even prefer:-) it!!
A user level that continues to overstate my experience :-))

Thanks You!!!

Maybe you want splice? But it's hard to tell, as you don't tell us exactly what you want to achieve.