# lib-rf-date.pl
# by Gav Ford
# revford@blueyonder.co.uk
# http://revford.pwp.blueyonder.co.uk
# 2008-03-28, updated 2008-09-26
# a collection of date related subroutines


# There are two date formats supported here, they are:
# ISO 8601  -  used for HTML -  2008-09-26T13:29:04Z
#                            -  2008-09-26
# RFC-822   -  used for RSS  -  Mon, 06 Oct 2008 13:29:04 GMT


%months = (Jan => '01', Feb => '02', Mar => '03', Apr => '04', May => '05', Jun => '06',
           Jul => '07', Aug => '08', Sep => '09', Oct => '10', Nov => '11', Dec => '12');


sub builddate {return('  <meta name="modified" content="' . cleandatelong() . '">')}
sub datestamp {return('<p class="subtitle">' . rssdate() . '</p>')}


sub cleandate
# ISO 8601 standard format
  {
  $daysago = $_[0];

  $longdate = gmtime(time() - ( 24 * 60 * 60 * $daysago)); # remove 24 hours, 60 mins, 60 sec * $daysago
  $longdate =~ s/\ \ /\ /;
  ($day, $month, $mday, $fullTime, $year) = split(/ /, $longdate);
  $mday = sprintf "%02d", "$mday";
  $monthnumber = $months{$month};

  return ("$year-$monthnumber-$mday");
  }



sub cleandatelong
# ISO 8601 standard format
  {
  $daysago = $_[0];

  $longdate = gmtime(time() - ( 24 * 60 * 60 * $daysago)); # remove 24 hours, 60 mins, 60 sec * $daysago
  $longdate =~ s/\ \ /\ /;
  ($day, $month, $mday, $fullTime, $year) = split(/ /, $longdate);
  $mday = sprintf "%02d", "$mday";
  $monthnumber = $months{$month};

  return ($year . '-' . $monthnumber . '-' . $mday . 'T' . $fullTime . 'Z');
  }



sub rssdate
# RFC-822 standard format, GMT
  {
  $daysago = $_[0];

  $longdate = gmtime(time() - ( 24 * 60 * 60 * $daysago));
  $longdate =~ s/\ \ /\ /;
  ($day, $month, $mday, $fullTime, $year) = split(/ /, $longdate);
  $mday = sprintf "%02d", "$mday";

  return ("$day, $mday $month $year $fullTime GMT");
  }



sub fulldate
# RFC-822 standard format, localtime
  {
  $daysago = $_[0];

  $longgmtdate = gmtime(time() - ( 24 * 60 * 60 * $daysago));
  $longgmtdate =~ s/\ \ /\ /;
  ($null, $null, $null, $fullTimeGMT) = split(/ /, $longgmtdate);

  $longdate = localtime(time() - ( 24 * 60 * 60 * $daysago));
  $longdate =~ s/\ \ /\ /;
  ($day, $month, $mday, $fullTime, $year) = split(/ /, $longdate);

  if ($fullTime eq $fullTimeGMT) {$timezone = "GMT"}

# Options for either the BST code or the difference from GMT, +0100
  #else {$timezone = "BST"}
  else {$timezone = "+0100"}

  $mday = sprintf "%02d", "$mday";

  return ("$day, $mday $month $year $fullTime $timezone");
  }



sub moddate
# turn an RSS date into a moddate, for sorting the posts list
  {
  my $thisdate = $_[0];

  $thisdate =~ s/\ \ /\ /;
  ($day, $mday, $month, $year, $fullTime) = split(/ /, $thisdate);
  $fullTime =~ s/://g;

  return ("$year$months{$month}$mday$fullTime");
  }


1;