From: Serg Koren <skoren@...>
Date: 2008-02-29T11:07:46+09:00
Subject: Re: Getting number of days in a month -- getting the number of weeks in a year.

Good job.  That's exactly what I meant.



On Feb 28, 2008, at 9:01 PM, Rick DeNatale wrote:

> On 2/28/08, Serg Koren <skoren@comcast.net> wrote:
>> A more interesting question is how do you get the number of weeks  
>> in a
>> year.
>> Some years have 52...some have 54.  Calendar weeks...not 7 day weeks.
>
> I assume you mean here how many 7 day weeks starting on a particular
> week day have at least one day in a given year.
>
> If this is the case then in all but one case every year has 53
> 'weeks.'  The only exception is a leap year which starts on the last
> day of the week which has 54 weeks.
>
> for start in (1..7) do
>  for days in (365..366) do
>    s = "a #{{365 => 'normal', 366 => 'leap'}[days]} year starting on
> weekday #{start} starts with "
>    start_week_days = start == 1 ? 0 : (8 - start)
>    s << "a 'week' of #{start_week_days} days then " unless  
> start_week_days == 0
>    days_remaining = days - start_week_days
>    full_weeks = days_remaining / 7
>    end_week_days = days_remaining % 7
>    s << "#{full_weeks} full weeks"
>    s << " and ends with a 'week' of #{end_week_days} days" unless
> end_week_days == 0
>    s << " a total of #{(start_week_days > 0 ? 1 : 0) + full_weeks +
> (end_week_days > 0 ? 1 : 0)} 'weeks.'"
>    puts s
>  end
>  puts
> end
>
>
> a normal year starting on weekday 1 starts with 52 full weeks and ends
> with a 'week' of 1 days a total of 53 'weeks.'
> a leap year starting on weekday 1 starts with 52 full weeks and ends
> with a 'week' of 2 days a total of 53 'weeks.'
>
> a normal year starting on weekday 2 starts with a 'week' of 6 days
> then 51 full weeks and ends with a 'week' of 2 days a total of 53
> 'weeks.'
> a leap year starting on weekday 2 starts with a 'week' of 6 days then
> 51 full weeks and ends with a 'week' of 3 days a total of 53 'weeks.'
>
> a normal year starting on weekday 3 starts with a 'week' of 5 days
> then 51 full weeks and ends with a 'week' of 3 days a total of 53
> 'weeks.'
> a leap year starting on weekday 3 starts with a 'week' of 5 days then
> 51 full weeks and ends with a 'week' of 4 days a total of 53 'weeks.'
>
> a normal year starting on weekday 4 starts with a 'week' of 4 days
> then 51 full weeks and ends with a 'week' of 4 days a total of 53
> 'weeks.'
> a leap year starting on weekday 4 starts with a 'week' of 4 days then
> 51 full weeks and ends with a 'week' of 5 days a total of 53 'weeks.'
>
> a normal year starting on weekday 5 starts with a 'week' of 3 days
> then 51 full weeks and ends with a 'week' of 5 days a total of 53
> 'weeks.'
> a leap year starting on weekday 5 starts with a 'week' of 3 days then
> 51 full weeks and ends with a 'week' of 6 days a total of 53 'weeks.'
>
> a normal year starting on weekday 6 starts with a 'week' of 2 days
> then 51 full weeks and ends with a 'week' of 6 days a total of 53
> 'weeks.'
> a leap year starting on weekday 6 starts with a 'week' of 2 days then
> 52 full weeks a total of 53 'weeks.'
>
> a normal year starting on weekday 7 starts with a 'week' of 1 days
> then 52 full weeks a total of 53 'weeks.'
> a leap year starting on weekday 7 starts with a 'week' of 1 days then
> 52 full weeks and ends with a 'week' of 1 days a total of 54 'weeks.'
>
> Or did you mean something else.
>
> -- 
> Rick DeNatale
>
> My blog on Ruby
> http://talklikeaduck.denhaven2.com/
>