I am trying to parse a string 26/03/2012, in dd/mm/yyyy format to Ruby's Date using Date.strptime, as follows:
#!/usr/bin/ruby
require 'date'
puts 'Ruby Version: ' + RUBY_VERSION
date_str = '26/03/2012'
date = Date.strptime(date_str, "%d/%m/%y")
puts 'Parsed Date: ' + date.to_s
The output is:
Ruby Version: 1.8.7
Parsed Date: 2020-03-26
The year part has become 2020, instead of 2012!
That should be %Y upper case, rather than %y:
date = Date.strptime(date_str, "%d/%m/%Y")
puts 'Parsed Date: ' + date.to_s
# Parsed Date: 2012-03-26
Date (Year, Month, Day):
%Y - Year with century (can be negative, 4 digits at least)
-0001, 0000, 1995, 2009, 14292, etc.
%C - year / 100 (round down. 20 in 2009)
%y - year % 100 (00..99)
Since %y expects two digits only, it takes the first two 20 and assumes that to be a 2 digit representation of 2020, since 2020 % 100 = 20.
%y - year % 100 indicates that all 4 digits of the year part should be read, if it reads first 2 digits only then there is no point of doing year % 100, which would same as year when year < 100! But as you say it perhaps reads only first 2 digits!(00..99) in the docs, this part is contradicting the %y - year % 100 part! Is not it? :)%y - year / 100, tried with 4042 as the year and it printed 2040 as the year. Had it been doing %y - year % 100 I would got what I wanted.
year % 100, so if you give it 20 as the result of year % 100, it extrapolates the current century. The %y - part isnt't subtraction, it's just how they printed it in the docs. No calculation takes place.2040 from 4042 is exactly expected because again, 2040 % 100 = 40. It expects 2 digits and uses the first 2 it finds. The others are discarded because it doesn't realize you are trying to give it the year 4042, it just sees a string "4042"If you change your strptime function to
date = Date.striptime(date_str, "%d/%m/%Y")
it will output correctly.
