How to represent Date before epoch as a integer

ruby-talk
1

Hi,

I provide a people search function that a user can specify a age range.
I use acts_as_ferret for the search.

I'd like to represent a user's birth date as a integer number, so that I
can tell Ferret to do the comparision easily.

#calculate birth date based on the given age
  def self.birth_date(age)
    born = Date.today
    Date.new(born.year - age, born.month, born.day)
  end

# get the birth date of the user that's 50 years old
User.birth_date(50).to_time

But I got this error:
ArgumentError: argument out of range
        from
C:/InstantRails-1.6-win/ruby/lib/ruby/gems/1.8/gems/activesupport-1
.4.1/lib/active_support/core_ext/date/conversions.rb:29:in `local'
        from
C:/InstantRails-1.6-win/ruby/lib/ruby/gems/1.8/gems/activesupport-1
.4.1/lib/active_support/core_ext/date/conversions.rb:29:in `send'
        from
C:/InstantRails-1.6-win/ruby/lib/ruby/gems/1.8/gems/activesupport-1
.4.1/lib/active_support/core_ext/date/conversions.rb:29:in `to_time'

I think the time can't be before unix epoch
time(http://en.wikipedia.org/wiki/Unix_epoch it is the number of seconds
elapsed since midnight UTC of January 1, 1970, not counting leap
seconds. )

Please advice how I can get around this limitation.

Thanks.
Yaxm

···

--
Posted via http://www.ruby-forum.com/.

2

Hi,

I provide a people search function that a user can specify a age range.
I use acts_as_ferret for the search.

I'd like to represent a user's birth date as a integer number, so that I
can tell Ferret to do the comparision easily.

#calculate birth date based on the given age
  def self.birth_date(age)
    born = Date.today
    Date.new(born.year - age, born.month, born.day)
  end

Strange this works perfectly on my box
irb(main):027:0> def birth_date(age)
irb(main):028:1> born = Date.today
irb(main):029:1> Date.new( born.year - age, born.month, born.day )
irb(main):030:1> end
=> nil
irb(main):031:0> birth_date 50
=> #<Date: 4871917/2,0,2299161>
irb(main):032:0> birth_date( 50 ).year
=> 1957

*However* this is code that does not work for all values on Feb 29th,
be careful about this

irb(main):033:0> Date.new( 2007, 2, 29 )
ArgumentError: invalid date
        from /usr/local/lib/ruby/1.8/date.rb:727:in `new'
        from (irb):33

# get the birth date of the user that's 50 years old
User.birth_date(50).to_time

But I got this error:
ArgumentError: argument out of range
        from
C:/InstantRails-1.6-win/ruby/lib/ruby/gems/1.8/gems/activesupport-1
.4.1/lib/active_support/core_ext/date/conversions.rb:29:in `local'
        from
C:/InstantRails-1.6-win/ruby/lib/ruby/gems/1.8/gems/activesupport-1
.4.1/lib/active_support/core_ext/date/conversions.rb:29:in `send'
        from
C:/InstantRails-1.6-win/ruby/lib/ruby/gems/1.8/gems/activesupport-1
.4.1/lib/active_support/core_ext/date/conversions.rb:29:in `to_time'

Form my expample and the stacktrace one can conclude that this is an
ActiveSupport issue. If I am not mistaken they have a method like
#years_ago
somewhere (probably adressing the Feb, 29 issue), sorry never used that stuff.

I think the time can't be before unix epoch
time(Unix time - Wikipedia it is the number of seconds
elapsed since midnight UTC of January 1, 1970, not counting leap
seconds. )

Hopefully you can, sure somebody knowing ActiveSupport will tell us about it

Robert

···

On 4/30/07, Yaxm Yaxm <snowstorm+rubyforum@gmail.com> wrote:
--
You see things; and you say Why?
But I dream things that never were; and I say Why not?
-- George Bernard Shaw

3

Hi,

At Mon, 30 Apr 2007 09:35:06 +0900,
Yaxm Yaxm wrote in [ruby-talk:249588]:

I'd like to represent a user's birth date as a integer number, so that I
can tell Ferret to do the comparision easily.

Date supports Julian Day Number.

Date.today.jd #=> 2454221

···

--
Nobu Nakada

4

Rober,
converting the date object to be a time can cause the exception:

birth_date(50)

=> #<Date: 4871917/2,0,2299161>

birth_date(50).to_time

ArgumentError: argument out of range

Time.new().years_ago(50) causes the same exception

Robert Dober wrote:

···

On 4/30/07, Yaxm Yaxm <snowstorm+rubyforum@gmail.com> wrote:

  def self.birth_date(age)
    born = Date.today
    Date.new(born.year - age, born.month, born.day)
  end

Strange this works perfectly on my box
irb(main):027:0> def birth_date(age)
irb(main):028:1> born = Date.today
irb(main):029:1> Date.new( born.year - age, born.month, born.day )
irb(main):030:1> end
=> nil
irb(main):031:0> birth_date 50
=> #<Date: 4871917/2,0,2299161>
irb(main):032:0> birth_date( 50 ).year
=> 1957

*However* this is code that does not work for all values on Feb 29th,
be careful about this

irb(main):033:0> Date.new( 2007, 2, 29 )
ArgumentError: invalid date
        from /usr/local/lib/ruby/1.8/date.rb:727:in `new'
        from (irb):33

C:/InstantRails-1.6-win/ruby/lib/ruby/gems/1.8/gems/activesupport-1
.4.1/lib/active_support/core_ext/date/conversions.rb:29:in `send'
        from
C:/InstantRails-1.6-win/ruby/lib/ruby/gems/1.8/gems/activesupport-1
.4.1/lib/active_support/core_ext/date/conversions.rb:29:in `to_time'

Form my expample and the stacktrace one can conclude that this is an
ActiveSupport issue. If I am not mistaken they have a method like
#years_ago
somewhere (probably adressing the Feb, 29 issue), sorry never used that
stuff.

I think the time can't be before unix epoch
time(Unix time - Wikipedia it is the number of seconds
elapsed since midnight UTC of January 1, 1970, not counting leap
seconds. )

Hopefully you can, sure somebody knowing ActiveSupport will tell us
about it

Robert

--
Posted via http://www.ruby-forum.com/\.

5

yeah. using Julian Day number works.

But there's no years_ago method in date class.

guess I need to write one.

Thanks.

Nobuyoshi Nakada wrote:

···

Hi,

At Mon, 30 Apr 2007 09:35:06 +0900,
Yaxm Yaxm wrote in [ruby-talk:249588]:

I'd like to represent a user's birth date as a integer number, so that I
can tell Ferret to do the comparision easily.

Date supports Julian Day Number.

Date.today.jd #=> 2454221

--
Posted via http://www.ruby-forum.com/\.

6

Hi,

At Tue, 1 May 2007 12:01:51 +0900,
Yaxm Yaxm wrote in [ruby-talk:249770]:

yeah. using Julian Day number works.

But there's no years_ago method in date class.

$ ruby -rdate -e 'puts Date.today << 50 * 12'
1957-05-01

···

--
Nobu Nakada

7

Why do you use Time? Does Date not do the job?
#years_ago is a method of the ActiveRecord extension of Date.
I guess we might not be talking about the same thing, maybe if you
post more code?
But look at Nobu's suggestion, seems to work just fine.

Cheers
Robert

···

On 5/1/07, Yaxm Yaxm <snowstorm+rubyforum@gmail.com> wrote:

Rober,
converting the date object to be a time can cause the exception:
>> birth_date(50)
=> #<Date: 4871917/2,0,2299161>
>> birth_date(50).to_time
ArgumentError: argument out of range

Time.new().years_ago(50) causes the same exception

--
You see things; and you say Why?
But I dream things that never were; and I say Why not?
-- George Bernard Shaw