OP didn't actually use "@days". However to illustrate the difference:

use strict;

my @days;
@days = qw(Monday Tuesday Wednesday Thursday Friday Saturday Sunday);

local $" = ', ';
print "@days\n";
print @days, "\n"
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Prints:

Monday, Tuesday, Wednesday, Thursday, Friday, Saturday, Sunday
MondayTuesdayWednesdayThursdayFridaySaturdaySunday
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