DZone Snippets: dates code

Display the number of characters in the name of each month

logankoester (Logan Koester) — Wed, 08 Aug 2007 01:59:52 GMT



months = %w(January February March April May June July August September October November December)

months.each { |m| print  m, " (", m.length, ")\n" }

Rewrite Apache logs that have incorrect dates

iansealy (Ian Sealy) — Sat, 02 Jun 2007 07:26:38 GMT

// Rewrite Apache logs that have incorrect dates



#!/usr/bin/perl



# $Id$



# Rewrite Apache logs that have incorrect dates.

# Example usage: $0 '28/May/2006:01:17:14 +0200' '19/Jan/2007:08:49:14 +0100' \

#                access_log.* error_log.*



use strict;

use warnings;



## no critic (ValuesAndExpressions::RequireInterpolationOfMetachars)

our ($VERSION) = '$Revision$' =~ m{ \$Revision: \s+ (\S+) }xms;

## use critic



use HTTP::Date;



my @DAYS   = qw(Sun Mon Tue Wed Thu Fri Sat);

my @MONTHS = qw(Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec);



my $wrong_datetime = shift @ARGV;

my $right_datetime = shift @ARGV;



my ($timezone) = $right_datetime =~ m/ ([+-]\d\d\d\d)\z/xms;



my $seconds_diff = str2time($right_datetime) - str2time($wrong_datetime);



foreach my $file (@ARGV) {

    print "Rewriting $file\n";

    open my $IN,  '<', $file

        or die "Can't open $file: $!\n";

    open my $OUT, '>', "$file.rewritten"

        or die "Can't write to $file.rewritten: $!\n";

    while (<$IN>) {

        if (m{

               \A

               (.+\s+) # Before date and time (if any)

               \[

               (

                   \d\d/\w\w\w/\d\d\d\d # Date

                   :\d\d:\d\d:\d\d      # Time

                   \s

                   [\+\-]\d\d\d\d       # Time zone

               )

               \]

               (\s+.+) # After date and time

               \z

             }xms) {

            print {$OUT} 

              $1, q{[},

              rewrite_access_datetime($2, $seconds_diff, $timezone),

              q{]}, $3;

        }

        elsif (m{

               \A

               \[

               (

                   \w\w\w \s \w\w\w \s \d\d \s # Date

                   \d\d:\d\d:\d\d \s           # Time

                   \d\d\d\d                    # Year

               )

               \]

               (\s+.+) # After date and time

               \z

             }xms) {

            print {$OUT} 

              q{[},

              rewrite_error_datetime($1, $seconds_diff),

              q{]}, $2;

        }

        else {

            print {$OUT} $_;

        }

    }

}



sub rewrite_access_datetime {

    my ($datetime, $seconds_diff, $timezone) = @_;

    

    my ($sign, $hours, $minutes) = $timezone =~ m/\A([+-])(\d\d)(\d\d)\z/xms;

    my $seconds_offset = ($hours * 60 + $minutes) * 60;

    

    $datetime = str2time($datetime) + $seconds_diff;

    if    ($sign eq q{+}) {

        $datetime = $datetime + $seconds_offset;

    }

    elsif ($sign eq q{-}) {

        $datetime = $datetime - $seconds_offset;

    }

    

    my ($sec, $min, $hour, $mday, $mon, $year) = gmtime $datetime;

    return sprintf '%02d/%s/%04d:%02d:%02d:%02d %s',

        $mday, $MONTHS[$mon], $year + 1900, $hour, $min, $sec, $timezone;

}



sub rewrite_error_datetime {

    my ($datetime, $seconds_diff) = @_;

    

    $datetime = str2time($datetime) + $seconds_diff;

    

    my ($sec, $min, $hour, $mday, $mon, $year, $wday) = gmtime $datetime;

    return sprintf '%s %s %02d %02d:%02d:%02d %04d',

        $DAYS[$wday], $MONTHS[$mon], $mday, $hour, $min, $sec, $year + 1900;

}

Date.distance_to method for Ruby

timmorgan (Tim Morgan) — Sat, 27 May 2006 00:58:55 GMT

Gives years, months, and days between two dates (like a human would expect)



class Date

  def distance_to(end_date)

    years = end_date.year - year

    months = end_date.month - month

    days = end_date.day - day

    if days < 0

      days += 30

      months -= 1

    end

    if months < 0

      months += 12

      years -= 1

    end

    {:years => years, :months => months, :days => days}

  end

end

Turn a date range into SQL conditions

peter (Peter Cooperx) — Wed, 01 Feb 2006 04:48:09 GMT

From here on Project.ioni.st.

(6.months.ago.to_date..1.year.ago.to_date).to_s(:db)

=> "BETWEEN '2005-07-27' AND '2005-01-22'"

work days between two dates without cycling through dates

Will_Rickards (Will Rickards) — Thu, 13 Oct 2005 23:24:13 GMT

I was thinking about how to optimize figuring out the work days between two dates and came up with this function. It doesn't take into account holidays. You would have to take out the workdays for holidays from the number if you want to take into account holidays, but that should be easy enough.

4GL Version

 

# workdays

# returns the number of working days between two dates

FUNCTION workdays( dt_begin, dt_end )



DEFINE

   dt_begin             DATE,

   dt_end               DATE,

   dt_first_sunday      DATE,

   dt_last_saturday     DATE,

   int_workdays         INTEGER



   # get first sunday

   LET dt_first_sunday = dt_begin + ((7 - WEEKDAY(dt_begin)) MOD 7)



   # get last saturday

   LET dt_last_saturday = dt_end + ((-1 * (WEEKDAY(dt_end) + 1)) MOD 7)



   # get work weeks between first sunday and last saturday

   LET int_workdays = (((dt_last_saturday - dt_first_sunday) + 1) / 7) * 5

   

   # if first sunday is not begin date

   IF dt_first_sunday <> dt_begin THEN



      # assume first sunday is after begin date

      # add workdays from begin date to first sunday

      LET int_workdays = int_workdays + (6 - WEEKDAY(dt_begin))



   END IF



   # if last saturday is not end date

   IF dt_last_saturday <> dt_end THEN



      # assume last saturday is before end date

      # add workdays from last saturday to end date

      LET int_workdays = int_workdays + WEEKDAY(dt_end)  

  

   END IF



   # return working days

   RETURN int_workdays



END FUNCTION

VBA Version



' WorkDays

' returns the number of working days between two dates

Public Function WorkDays(ByVal dtBegin As Date, ByVal dtEnd As Date) As Long



   Dim dtFirstSunday As Date

   Dim dtLastSaturday As Date

   Dim lngWorkDays As Long



   ' get first sunday in range

   dtFirstSunday = dtBegin + ((8 - Weekday(dtBegin)) Mod 7)



   ' get last saturday in range

   dtLastSaturday = dtEnd - (Weekday(dtEnd) Mod 7)



   ' get work days between first sunday and last saturday

   lngWorkDays = (((dtLastSaturday - dtFirstSunday) + 1) / 7) * 5



   ' if first sunday is not begin date

   If dtFirstSunday <> dtBegin Then



      ' assume first sunday is after begin date

      ' add workdays from begin date to first sunday

      lngWorkDays = lngWorkDays + (7 - Weekday(dtBegin))



   End If



   ' if last saturday is not end date

   If dtLastSaturday <> dtEnd Then



      ' assume last saturday is before end date

      ' add workdays from last saturday to end date

      lngWorkDays = lngWorkDays + (Weekday(dtEnd) - 1)



   End If



   ' return working days

   WorkDays = lngWorkDays



End Function