# Re: Ordinal Date String to Standard Date String for a Beginn **URL:** \ **Category:** Ruby\ **Created:** [November 18, 2005, 10:46am UTC](https://www.ruby-forum.com/t/re-ordinal-date-string-to-standard-date-string-for-a-beginn/48260 "2005-11-18T10:46:13Z")\ **Posts on this page:** 9\ **Page:** 1
**Author:** ![botp](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/b/258eb7/32.png) [@botp](https://www.ruby-forum.com/u/botp)\ **Post date:** [November 18, 2005, 10:46am UTC](https://www.ruby-forum.com/t/re-ordinal-date-string-to-standard-date-string-for-a-beginn/48260/1 "2005-11-18T10:46:13Z")
davyb [[mailto:removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid)] #I have an ordinal date string and I want to change it to an ordinary #date string. For example: 2005/1 should give January 1, 2005. I see #ordinal in the Date class but I need a simple example. Thanks, i hope this is simple enough. # we want to get the year and day values fr your string > re = /(\d+)/(\d+)/ =\> /(\d+)/(\d+)/ > rs = “2005/1” =\> “2005/1” > y,d=re.match(rs)[1…2] =\> [“2005”, “1”] # we need to convert them to integers since ordinal wants num > y = y.to\_i =\> 2005 > d = d.to\_i =\> 1 > od = Date.ordinal(y,d) =\> #\ # we got a date object # fr here we can do anything > od.year =\> 2005 > od.month =\> 1 > od.day =\> 1 > nd\_str1 = od.to\_s =\> “2005-01-01” > nd\_str2 = od.strftime(“%B %e, %Y”) =\> “January 1, 2005” > nd\_str3 = nd\_str2.squeeze(" ") =\> “January 1, 2005” hth. kind regards -botp #Dave ---
**Author:** ![botp](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/b/258eb7/32.png) [@botp](https://www.ruby-forum.com/u/botp)\ **Post date:** [November 18, 2005, 11:58am UTC](https://www.ruby-forum.com/t/re-ordinal-date-string-to-standard-date-string-for-a-beginn/48260/2 "2005-11-18T11:58:46Z")
Botp, Todd, Thanks. Since I had already parsed the ordinal date’s year and day to get them in string sortable order, I just had to take your examples and do this: require ‘date’ … od = Date.ordinal (strYear.to\_i, strOrdn.to\_i) and then od.to\_s gives the sortable (and readable) yyyy-mm-dd string. Wow, Ruby is powerful, but the documentation on Date (and perhaps other gem filled libraries) is hard for a beginner to grok. I found Date’s ordinal with a Google search, which gave me the built-in documentation, but no examples. So, if I need at least the APIs for a library such as Date I use “ri”? Thanks again, Dave PS Here’s the beginner’s way I used to parse the ordinal date string (eg “2005/17”): strYear = strDate[strDate.index("/")+1, strDate.length] strOrdn = strDate[0, strDate.index("/")] ---
**Author:** ![botp](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/b/258eb7/32.png) [@botp](https://www.ruby-forum.com/u/botp)\ **Post date:** [November 18, 2005, 12:01pm UTC](https://www.ruby-forum.com/t/re-ordinal-date-string-to-standard-date-string-for-a-beginn/48260/3 "2005-11-18T12:01:46Z")
Yeah, it’s backwards in the PS – just noticed it. (str.reverse won’t help!!!) ---
**Author:** ![botp](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/b/258eb7/32.png) [@botp](https://www.ruby-forum.com/u/botp)\ **Post date:** [November 18, 2005, 7:59pm UTC](https://www.ruby-forum.com/t/re-ordinal-date-string-to-standard-date-string-for-a-beginn/48260/4 "2005-11-18T19:59:36Z")
David Boyd wrote: > Botp, Todd, > Thanks. Since I had already parsed the ordinal date’s year and day to get > them in string sortable order, I just had to take your examples and do this: > require ‘date’ … od = Date.ordinal (strYear.to\_i, strOrdn.to\_i) and then > od.to\_s gives the sortable (and readable) yyyy-mm-dd string. > Wow, Ruby is powerful, but the documentation on Date (and perhaps other gem > filled libraries) is hard for a beginner to grok. I found Date’s ordinal > with a Google search, which gave me the built-in documentation, but no > examples. So, if I need at least the APIs for a library such as Date I use > “ri”? Yeah, no examples. I guess they just expect us to learn it from them directly 🙂 Todd ---
**Author:** ![botp](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/b/258eb7/32.png) [@botp](https://www.ruby-forum.com/u/botp)\ **Post date:** [November 18, 2005, 8:08pm UTC](https://www.ruby-forum.com/t/re-ordinal-date-string-to-standard-date-string-for-a-beginn/48260/5 "2005-11-18T20:08:39Z")
David Boyd wrote: > PS Here’s the beginner’s way I used to parse the ordinal date string (eg > “2005/17”): > > strYear = strDate[strDate.index("/")+1, strDate.length] > strOrdn = strDate[0, strDate.index("/")] strYear, strOrdn = “2005/17”.split("/") ---
**Author:** ![botp](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/b/258eb7/32.png) [@botp](https://www.ruby-forum.com/u/botp)\ **Post date:** [November 18, 2005, 8:14pm UTC](https://www.ruby-forum.com/t/re-ordinal-date-string-to-standard-date-string-for-a-beginn/48260/6 "2005-11-18T20:14:42Z")
Oh, and strftime doesn’t show up in the online RDoc documentation ([http://www.ruby.org/core](http://www.ruby.org/core)). Sometimes, stuff like this gets a little frustrating so I end up using .public\_methods or .instance\_methods to find out what’s cooking underneath the hood. I understand keeping docs up to date for a relatively volatile language like Ruby is difficult. It does say at the top of the Date doc: See the documentation to the file date.rb for an overview. This is on the same page, upper left frame, called lib/date.rb. There are a couple examples there. ri doesn’t work on my machine for some reason. I probably just have to reinstall it. Todd ---
**Author:** ![botp](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/b/258eb7/32.png) [@botp](https://www.ruby-forum.com/u/botp)\ **Post date:** [November 18, 2005, 8:32pm UTC](https://www.ruby-forum.com/t/re-ordinal-date-string-to-standard-date-string-for-a-beginn/48260/7 "2005-11-18T20:32:48Z")
On Sat, 19 Nov 2005, Todd wrote: > Oh, and strftime doesn’t show up in the online RDoc documentation > ([http://www.ruby.org/core](http://www.ruby.org/core)). Sometimes, stuff like this gets a little [http://www.ruby-doc.org/stdlib/libdoc/date/rdoc/classes/Date.html#M000404](http://www.ruby-doc.org/stdlib/libdoc/date/rdoc/classes/Date.html#M000404) [http://www.ruby-doc.org/stdlib/libdoc/date/rdoc/classes/DateTime.html#M000416](http://www.ruby-doc.org/stdlib/libdoc/date/rdoc/classes/DateTime.html#M000416) ``` Hugh ``` ---
**Author:** ![botp](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/b/258eb7/32.png) [@botp](https://www.ruby-forum.com/u/botp)\ **Post date:** [November 20, 2005, 9:38am UTC](https://www.ruby-forum.com/t/re-ordinal-date-string-to-standard-date-string-for-a-beginn/48260/8 "2005-11-20T09:38:30Z")
How elegant! Thanks! Dave ---
**Author:** ![botp](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/b/258eb7/32.png) [@botp](https://www.ruby-forum.com/u/botp)\ **Post date:** [November 18, 2005, 10:09pm UTC](https://www.ruby-forum.com/t/re-ordinal-date-string-to-standard-date-string-for-a-beginn/48260/9 "2005-11-18T22:09:23Z")
Hugh S. wrote: > On Sat, 19 Nov 2005, Todd wrote: > > > Oh, and strftime doesn’t show up in the online RDoc documentation > > ([http://www.ruby.org/core](http://www.ruby.org/core)). Sometimes, stuff like this gets a little > > [http://www.ruby-doc.org/stdlib/libdoc/date/rdoc/classes/Date.html#M000404](http://www.ruby-doc.org/stdlib/libdoc/date/rdoc/classes/Date.html#M000404) > [http://www.ruby-doc.org/stdlib/libdoc/date/rdoc/classes/DateTime.html#M000416](http://www.ruby-doc.org/stdlib/libdoc/date/rdoc/classes/DateTime.html#M000416) > > ``` > Hugh > > ``` Oops, I meant [RDoc Documentation](http://www.ruby-doc.org/core) So, I guess I should really be looking at the Standard Library API instead of the Core API link from now on? Todd