# Time granularity **URL:** \ **Category:** ruby-talk\ **Created:** [27 February 2007 17:59 UTC](https://rubytalk.org/t/time-granularity/35719 "2007-02-27T17:59:28Z")\ **Posts on this page:** 6\ **Page:** 1
**Author:** ![Guest16](https://avatars.discourse-cdn.com/v4/letter/g/779978/32.png) [@Guest16](https://rubytalk.org/u/Guest16)\ **Post date:** [27 February 2007 17:59 UTC](https://rubytalk.org/t/time-granularity/35719/1 "2007-02-27T17:59:28Z")
Hello, I need to create some time variables for our company's accounting budget calendar. We have 13 budget periods in a year. The first one ends on the last Sunday of January of whatever year it is. Once I find that day, then I can simply add 28 days to it, consecutively, to get the remaining budget fences. Anyway, I'm basically just starting with the 31st of January and working back until I find the last Sunday of the month. I've tried a string of if/elsif statements and I get close, but, it seems to me I could do it with less code. If I create a range between that last day of the month and all 7 days prior to it, that last Sunday should be in there somewhere. When I try to work with ranges, though, and ask for any results, it returns results for literally every second of every day in that range! So, can anyone help me to ask Ruby to just give me days back and not any subdivisions of those days? t1 = Time.mktime(2007,1,24) t2 = Time.mktime(2007,1,31) dates = t1 .. t2 dates.each for |date|   ... #puts "date is a Sunday."   end end > **···** > > -- > Posted via [http://www.ruby-forum.com/](http://www.ruby-forum.com/). ---
**Author:** ![Kirk\_Haines](https://avatars.discourse-cdn.com/v4/letter/k/c6cbf5/32.png) [@Kirk\_Haines](https://rubytalk.org/u/Kirk_Haines)\ **Post date:** [27 February 2007 18:15 UTC](https://rubytalk.org/t/time-granularity/35719/2 "2007-02-27T18:15:03Z")
Do it with Date instead of Time. require 'date' t1 = Date.new(2007,1,24) t2 = Date.new(2007,1,31) dates = t1 .. t2 dates.each do |date|    # your date stuff here end Time uses seconds to represents a point in time. Time is fast, because it's really just a thin layer between Ruby and the underlying C libraries. Date and DateTime use days for their unit, represented by rational numbers (instances of the Rational class). They are a lot slower than Time objects, but have some flexibility that Time doesn't, and the use of Days for their unit means they work well for your application. If you want to convert a Date into a Time, do this: Time.local(date.year,date.month,date.day) Kirk Haines > **···** > > On Wed, 28 Feb 2007, Peter Bailey wrote: > > > me I could do it with less code. If I create a range between that last > > day of the month and all 7 days prior to it, that last Sunday should be > > in there somewhere. When I try to work with ranges, though, and ask for > > any results, it returns results for literally every second of every day > > in that range! So, can anyone help me to ask Ruby to just give me days > > back and not any subdivisions of those days? > > > > t1 = Time.mktime(2007,1,24) > > t2 = Time.mktime(2007,1,31) > > dates = t1 .. t2 > > dates.each for |date| > > ... #puts "date is a Sunday." > > end > > end ---
**Author:** ![Rob\_Biedenharn1](https://avatars.discourse-cdn.com/v4/letter/r/57b2e6/32.png) [@Rob\_Biedenharn1](https://rubytalk.org/u/Rob_Biedenharn1)\ **Post date:** [27 February 2007 19:15 UTC](https://rubytalk.org/t/time-granularity/35719/3 "2007-02-27T19:15:28Z")
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**Author:** ![Guest16](https://avatars.discourse-cdn.com/v4/letter/g/779978/32.png) [@Guest16](https://rubytalk.org/u/Guest16)\ **Post date:** [27 February 2007 19:39 UTC](https://rubytalk.org/t/time-granularity/35719/4 "2007-02-27T19:39:32Z")
This is perfect. Thanks, Kirk. > **···** > > -- > Posted via [http://www.ruby-forum.com/](http://www.ruby-forum.com/). ---
**Author:** ![Rob\_Biedenharn1](https://avatars.discourse-cdn.com/v4/letter/r/57b2e6/32.png) [@Rob\_Biedenharn1](https://rubytalk.org/u/Rob_Biedenharn1)\ **Post date:** [27 February 2007 21:35 UTC](https://rubytalk.org/t/time-granularity/35719/5 "2007-02-27T21:35:39Z")
> > me I could do it with less code. If I create a range between that last > > day of the month and all 7 days prior to it, that last Sunday should be > > in there somewhere. When I try to work with ranges, though, and ask for > > any results, it returns results for literally every second of every day > > in that range! So, can anyone help me to ask Ruby to just give me days > > back and not any subdivisions of those days? > > > > t1 = Time.mktime(2007,1,24) > > t2 = Time.mktime(2007,1,31) > > dates = t1 .. t2 > > dates.each for |date| > > ... #puts "date is a Sunday." > > end > > end > > Do it with Date instead of Time. > > require 'date' > t1 = Date.new(2007,1,24) > t2 = Date.new(2007,1,31) > dates = t1 .. t2 > dates.each do |date| >   # your date stuff here > end > > Time uses seconds to represents a point in time. Time is fast, because it's really just a thin layer between Ruby and the underlying C libraries. > > Date and DateTime use days for their unit, represented by rational numbers (instances of the Rational class). They are a lot slower than Time objects, but have some flexibility that Time doesn't, and the use of Days for their unit means they work well for your application. > > If you want to convert a Date into a Time, do this: > > Time.local(date.year,date.month,date.day) > > Kirk Haines Don't even deal with the range: \>\> jan31 = Date.new(2007,1,31) =\> #\ \>\> jan31.strftime "%D, %A" =\> "01/31/07, Wednesday" \>\> (jan31 - jan31.wday).strftime "%D, %A" =\> "01/28/07, Sunday" Date#wday is the number of the weekday: 0=\>Sunday, 6=\>Saturday \>\> (1999..2007).each do |year| ?\> jan31 = Date.new(year,1,31) \>\> puts (jan31 - jan31.wday).strftime("%D, %A") \>\> end; nil 01/31/99, Sunday 01/30/00, Sunday 01/28/01, Sunday 01/27/02, Sunday 01/26/03, Sunday 01/25/04, Sunday 01/30/05, Sunday 01/29/06, Sunday 01/28/07, Sunday Then start adding! \>\> jan31 = Date.new(2007,1,31) =\> #\ \>\> next\_jan31 = Date.new(2008,1,31) =\> #\ \>\> ((jan31-jan31.wday)...(next\_jan31-next\_jan31.wday)).step(28) do |day\> ?\> puts day.strftime("%D, %A") \>\> end;nil 01/28/07, Sunday 02/25/07, Sunday 03/25/07, Sunday 04/22/07, Sunday 05/20/07, Sunday 06/17/07, Sunday 07/15/07, Sunday 08/12/07, Sunday 09/09/07, Sunday 10/07/07, Sunday 11/04/07, Sunday 12/02/07, Sunday 12/30/07, Sunday -Rob Rob Biedenharn [http://agileconsultingllc.com](http://agileconsultingllc.com) Rob@AgileConsultingLLC.com > **···** > > On Feb 27, 2007, at 1:15 PM, khaines@enigo.com wrote: > > > On Wed, 28 Feb 2007, Peter Bailey wrote: ---
**Author:** ![Guest16](https://avatars.discourse-cdn.com/v4/letter/g/779978/32.png) [@Guest16](https://rubytalk.org/u/Guest16)\ **Post date:** [28 February 2007 12:48 UTC](https://rubytalk.org/t/time-granularity/35719/6 "2007-02-28T12:48:24Z")
Got it. Thanks. > **···** > > -- > Posted via [http://www.ruby-forum.com/](http://www.ruby-forum.com/).