How about you provide a piece of code that can be run and demonstrates the problem?

It is good practice to use strictures (use strict; use warnings;). That may not help highlight the problem in this case, but strictures are pretty good at catching typos and "silly" errors early rather than late and will save you bulk time and frustration one day soon. ;)

Update: for my $person ( 1 .. $#{$row_arr_today} ) does not "##cycle through the array" because Perl arrays start at 0 (generally). But you knew that because later you have foreach my $row ( 0 .. $#namearray ) so either the code of the comment is wrong, or at least is misleading. Generally it is considered bad to comment "obvious stuff". It's especially bad when the comment is wrong or misleading!