use Time::Local qw(timelocal);

# This function will return the date in a second from epoch time
# Example:
# my $timeInSec = getTimeInSec('2005-03-28 12:00:00');
# BUT
# actually function work with format '2005-03-28' if you need full date/time you have to make some changes.
# If you will have problem with it please contact me.

sub getTimeInSec {

    my $time = shift;
    my ( $year,$month,$day );

    if ( $time =~ /^
                   (\d\d\d\d)                  # Parsing Year
                   [-\x20.\/]?                 # Delimiter
                   (1[0-2]|0?[1-9])            # Parsing Month
                   [-\x20.\/]?                 # Delimiter
                   (3[0-1]|[1-2][0-9]|0?[1-9]) # Parsing Day
                   $
                  /x
                  or die "Date format '$time' is wrong"
       )
    {
         ( $year,$month,$day ) = ( $1,$2,$3 );
         die "Date format '$time' is wrong" unless &checkDateFormat( $year,$month,$day );
    }
    return timelocal(00,00,00,$day,$month-=1,$year-=1900);
}

# This function check if the given string is a correct date.

sub checkDateFormat {
    my ( $year,$month,$day ) = @_;

    my %month_day = ('01' => 31
                    ,'03' => 31
                    ,'02' => &checkLeapYear($year)
                    ,'04' => 30
                    ,'05' => 31
                    ,'06' => 30
                    ,'07' => 31
                    ,'08' => 31
                    ,'09' => 30
                    ,'10' => 31
                    ,'11' => 30
                    ,'12' => 31);

   $month = '0' . $month if length( $month ) == 1;
   return 1 if ($day <= $month_day{ $month });
   return 0;
}

sub checkLeapYear {
    return 29 unless $_[0] % 400;
    return 28 unless $_[0] % 100;
    return 29 unless $_[0] % 4;
    return 28;
}

# To use this function you can write
# printf "%04d-%02d-%02d %02d:%02d:%02d", &timenow();
# or
# my $dateTime = sprintf "%04d-%02d-%02d %02d:%02d:%02d", &timenow(getTimeInSec('2005-03-28 12:00:00'));

sub timenow {
    my ($sec,$min,$hour,$day,$month,$year) = localtime(defined $_[0] ? $_[0] : time);
    return $year+1900,$month+1,$day,$hour,$min,$sec;
}