You could make your own filter. For 100% accurate details on how to set this up take a look at the TT docs. But something like this should be close (there is extra stuff you need to do to package this routine i.e. putting it in a package, telling TT how to find the package etc. I don't have a ton of time right now so I'll leave you to dig.

sub ByDate
{
    my ($self, $text, $args, $conf) = @_;
    
    # Do appropriate time formatting
    $cooked_now = TimeFormat(time);
 
    if($cooked_now > $args->[0] && $cooked_now < $args->[1])
    {
       return $text;
    }
    else
    {
       return "";
    }
}
[download]

The TT code would look something like this

[% USE MyFilter %]

[% FILTER $MyFilter <start> <end> %]
Don't display this before <start> or after <end>
[% END %]
[download]

As I said, I forget exactly how the linkage between MyFilter and your code works, I do remember it's explained very well in the docs. Hope this helps.