Comments on: Calculate age in Rails with a birthday

By: CaDs

CaDs — Fri, 12 Jun 2009 06:47:07 +0000

This seems to do the job:

((Time.now.to_time – birthday.to_time) / 1.years).to_i

By: NOV

NOV — Sat, 10 May 2008 22:20:57 +0000

today, birthday = [Date.today, self].map do |d|
d.strftime(“%Y%m%d”).to_i
end
(today – birthday) / 10000

By: NOV

NOV — Sat, 10 May 2008 21:56:58 +0000

class Date
  def to_age
    integer_style = "%Y%m%d"
    today = Date.today.strftime(integer_style).to_i
    birthday = Date.today.strftime(integer_style).to_i
    (today - birthday) / 10000
  end
end

=> birthday.to_age

If the birthday.class.class_name == Time, you can use below.

http://d.hatena.ne.jp/secondlife/20050922/1127376501

By: rolf

rolf — Tue, 15 Apr 2008 14:03:39 +0000

def age(birthday)
    y=(Date.today.year) - (birthday.year)
    m=(Date.today.month)-(birthday.month)
    d=(Date.today.day)-(birthday.day)
        case 
           when (m<0) 
                      age=y-1 
           when (m=0)
                        case
                            when(d0)
                              age=y
                        end
            when (m>0)
              age=y
         end
    age
  end

By: rolf

rolf — Tue, 15 Apr 2008 13:56:49 +0000

I've put the next few lines in my application_helper, I'm using it to calculate the age of people today(but this could be any date), just passing @person.birthday to it. gr rolf

  def age(birthday)
    y=(Date.today.year) - (birthday.year)
    m=(Date.today.month)-(birthday.month)
    d=(Date.today.day)-(birthday.day)
        case 
           when (m<0) 
                      age=y-1     #april-mei=-1; april-april=0; april-maart=1#15-15=0; 15-16=-1; 15-13=2
           when (m=0)
                        case
                            when(d0)
                              age=y
                        end
            when (m>0)
              age=y
         end
    age
  end

By: api

api — Fri, 11 Apr 2008 14:29:33 +0000

( (Date.today – birthday).to_i / 365.25).floor this will work with leap-year

By: Naveen Dittakavi

Naveen Dittakavi — Mon, 24 Mar 2008 18:41:55 +0000

Hi Tobi, We couldn't get the above to work. Here's what worked for us in the controller:

birthday = Time.mktime(params[:year], params[:month].to_i, params[:day].to_i)
@age = age(birthday)

protected

def age( birthday )
age = Date.today.year - birthday.year
today = Time.now
age -= 1 if birthday > today.years_ago( age )
age
end

By: Tobi

Tobi — Thu, 13 Mar 2008 14:34:09 +0000

ups it should be:

def age( birthday )
    age = Date.today.year - birthday.year
    age -= 1 if birthday > Date.today.years_ago( age )
    age
end

By: Tobi

Tobi — Thu, 13 Mar 2008 14:32:23 +0000

Hey thanks for your solution.

The exact age with leap years seams a bit tricky. Unfortunately the above solution has still 2 problems:
1. it changes the actual birthday data which we may need later in progress
2. it raises an “InvalidDate Exception” if now is a leapyear day, e.g. 2008/2/29

I solved this with:

 def age( birthday )
    return 0 unless info.birthday
    age = Date.today.year - birthday.year
    age -= 1 if birthday > Date.today.years_ago( age )
    age
  end

check http://pastie.caboo.se/165173 for the belonging tests

By: anonymous

anonymous — Fri, 29 Feb 2008 05:33:34 +0000

i also was not aware of all the gotchas involved with dates, times and timezones…

somehow i missed this detail:
you cannot compare DateTime with Time, so use the to_date Method on both Objects

def age
now = Time.now.utc.to_date
now.year – birthday.year – (birthday.to_date.change(:year => now.year) > now ? 1 : 0)
end