How to represent Date before epoch as a integer

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:insend’
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

On 4/30/07, Yaxm Y. [email protected] 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:into_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(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. )
Hopefully you can, sure somebody knowing ActiveSupport will tell us
about it

Robert

Hi,

At Mon, 30 Apr 2007 09:35:06 +0900,
Yaxm Y. 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

yeah. using Julian Day number works.

But there’s no years_ago method in date class.

guess I need to write one.

Thanks.

Nobuyoshi N. wrote:

Hi,

At Mon, 30 Apr 2007 09:35:06 +0900,
Yaxm Y. 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

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 D. wrote:

On 4/30/07, Yaxm Y. [email protected] 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:into_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(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. )
Hopefully you can, sure somebody knowing ActiveSupport will tell us
about it

Robert

On 5/1/07, Yaxm Y. [email protected] 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

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

Hi,

At Tue, 1 May 2007 12:01:51 +0900,
Yaxm Y. 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

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