Routines to manage the FuzzyDate Class. There is also an extension to the
  ActiveRecord::Base class to provide an 'acts_as_fuzzy_date' class method.

  Historical dates are often incomplete or approximate and this class allows
  such dates to be worked with and stored on a database.

  construct a new object with FuzzyDate.new( year,month,day,wday,circa)
     year:   optional..is the year number 0 .. big as you like, -ve for BCE
     month:  optional.. is month number 1..12, or nil
     day:    optional.. is day number 1-31 or nil
     wday:   optional.. day of the week - 0=Sunday .. 6=Saturday
     circa:  true = day is approx, or nil/false

     note that if you supply the weekday and a year/month/day the system will
     use your weekday as supplied even if this does not actually correspond
     in reality to the date supplied.

   construct a new object with FuzzyDate.parse("date_string")
     date_string = eg: "tuesday"
                       "12 nov 1012"
                       "circa 412 bc"

   Use in a database table by storing in an integer field of a format large
   enough to hold the digits of your maximum year + 8. Eg. a BIGNUM field
   stores 19 useful characters allowing the year to go to 99,999,999,999.
   ie 99 billion years.

   Use with an ActiveRecord class ..

       require 'fuzzy_date'

       class HistoricalPerson < ActiveRecord::Base
           acts_as_fuzzy_date : birth_date, death_date
       end



Copyright (c) Clive Andrews / Reality Bites 2008, 2009, 2010, 2020

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.