Documention for: work-days.r
Created by: sunanda
 on: 18-Feb-2007
Format: text/editable
Downloaded on: 30-Apr-2025

[numbering-on
[contents

[asis
    Author: Sunanda
   Version: 1.0
      Date: 18-feb-2007
asis]

[h2 calculate working days

[p This script calculates the number of **working days**
between two dates.

[h2 examples:

[asis
    do %work-days.r
    calc-work-days now now + 7 []
    == 5   ;; working weeks have five working days

    calc-work-days 1-jan-2008 5-jan-2008 []
    == 3    ;; tue to sat is three working days (wed, thu, fri)
    calc-work-days/non 1-jan-2008 5-jan-2008 []
    == 1    ;; tue to sat is one non-working day (sat)
asis]

[h2 usage

[h3 starting the script
[asis do %work-days.r asis]

[h3 functions

[p There is just one function with one optional refinement:

[h4 calc-work-days **start**, **end**, **holidays**

[p Where:

[li **start** is the first date of the period
[li **end** is the last date of the period
[li **holidays** is a **block** of dates which are not working days
 (eg Christmas, Easter, and/or national holidays). The block must
 be supplied, but may be empty.
 list]
 
[h3 /non refinement
[p  ""inverts"" the output -- ie output is number of non-working days in the range.

[h2 definitions / specification

[li **Working days between two dates** means whole days, not including the first day in 
the range. Mon 1-jan to Mon 1-jan (ie the same day) is **zero** working days as
a **range** (It is of course, one working day if you have to work it)
[li A **working day** is defined as **Monday** through **Friday**. This is not a universally
accepted definition, though it does work well in most of the Western world. Please
feel free to chip in code changes to parameterise this definition.

list]

[h2 acknowledgements / credits

[p This script was written in response to a challenge on the
[link/fsl http://www.rebol.org/cgi-bin/cgiwrap/rebol/ml-display-thread.r?m=rmlTFJC "REBOL Mailing List"
to produce a better script.

[p Thanks to Ed O'Conner for providing that initial impetus.

[p His challenge came from seeing a 
[link/class/fsl http://www.railsonwave.com/railsonwave/2007/1/30/calculate-the-number-of-working-days-between-two-dates "RUBY version of the script." 
It is instructive to compare all the approaches used.

[p  [date