use strict;
use warnings;

my %monthOrd = (
    Jan => 1,
    Feb => 2,
    Mar => 3,
    Apr => 4,
    May => 5,
    Jun => 6,
    Jul => 7,
    Aug => 8,
    Sep => 9,
    Oct => 10,
    Nov => 11,
    Dec => 12,
);

my @records = grep {/\n/ and /[^\n]/} do {local $/ = "\n\n"; <DATA>};

s/^\n+|\n$//gs for @records;

for my $record (@records) {
    my @lines = split "\n", $record;

    $lines[0] //= '';

    my ($day, $month, $year, $time) = $lines[0] =~ /(\d+)\s+(\w+)(?:, (\d+))?\s+\@\s+(\S+)/;

    if(defined $month && exists $monthOrd{$month}) {
        $year ||= 2018;
        $lines[0] = sprintf "%04d %2d %2d %7s", $year, $monthOrd{$month}, $day, $time;
    } else {
        unshift @lines, '';
    }

    $record = \@lines;
}

# Sort records by not achieved first. Remove blank lines from records
@records = map {$_ = [grep {$_} @$_]; $_} sort {$a->[0] cmp $b->[0]} @records;

print join "\n", @$_, '', '' for @records;

__DATA__
Unlocked 18 Feb, 2016 @ 11:39pm
First in the Hearts of Your Countrymen
Beat the game on any difficulty setting as Washington.

Unlocked 2 Jun, 2016 @ 7:48pm
Video et Taceo
Beat the game on any difficulty setting as Elizabeth.

Unlocked 18 Nov, 2017 @ 4:57pm
Vivre La Revolution
Beat the game on any difficulty setting as Napoleon.

Unlocked 25 Apr, 2016 @ 9:44am
Blood and Iron
Beat the game on any difficulty setting as Bismarck.

Red Badge of Courage
Win the Civil War scenario on Deity.

Pickett's Recharge
Capture Gettysburg with a Confederate Infantry unit possessing the George Pickett promotion.

Sheridan's Valley Campaign
As Union, control Winchester, Front Royal, Harrisonburg, Staunton, and Lynchburg.