From: Charles Comstock <cc1@...>
Date: 2004-04-02T01:49:27+09:00
Subject: Re: How to get internal state of DateTime in seconds

> iff
>   - your times are a common format
>   - your times are within the ranges allowable by Time
> 
> both of which appear to be true why not simply parse the time yourself?  this
> is plenty clean, especially if it's in instance method of a LogEntry class or
> something:
> 
> 
> file: logtm.rb
> 
> def logtm s
> #{{{
>   pat = 
>     %r|^\s*(\d\d)/(\w\w\w)/(\d\d\d\d):(\d\d):(\d\d):(\d\d)\s+\+(\d\d)(\d\d)\s*$|io
> 
>   s = s.to_s
>   m = pat.match s
>   raise ArgumentError, "<#{ s.inspect }>" unless m
> 
>   parts = m.to_a
>   raise ArgumentError, "<#{ s.inspect }>" unless parts.size == 9  
> 
>   parts.shift
>   day, month, year, hour, min, sec, zhour, zmin = parts
> 
>   months = %w(jan feb mar apr may jun jul aug sep oct nov dec)
>   i = months.index month.downcase
>   raise ArgumentError, "<#{ s.inspect }>" unless i
>   month = i + 1
> 
>   day, month, year, hour, min, sec, zhour, zmin =
>     [day, month, year, hour, min, sec, zhour, zmin].map{|x| x.to_i}
> 
>   utc = Time.utc year, month, day, hour, min, sec, usec = 0
> 
>   t = utc + ((zhour * 60 * 60) + (zmin * 60)) 
> #}}}
> end
> 
> str1 = '20/Nov/2003:08:08:09 +0200'
> str2 = '20/Nov/2003:08:04:09 +0200'
> t1   = logtm str1
> t2   = logtm str2
> 
> #what is difference in minutes between these 2 times?
> p((t1 - t2).abs / 60.0) # => 4.0
> 
> 
> -a

Umm I don't understand how this relates, I can construct Time objects 
from strings just fine (parsedate), I want a library to take the time 
difference in seconds from two Time or Date objects, and format output 
of that into something meaningful, ie %H:%M:%S would result in 
"00:04:00" for your example difference.  But it should scale all the way 
up to differences in Months/Years.  It seems like a perfectly useful 
library, and I was suprised it hadn't been written.  Yes it's just 
division up to months, and then months cares what the actual start/end 
times were, but still it seems like a useful object.  Seconds is all 
fine and good when your just recording short ranges, but for longer...

Charles Comstock