Date Comparison and Manipulation Functions?

[W. eWatson]

John Machin wrote:
> On Aug 30, 10:41 am, "W. eWatson" <notval... at sbcglobal.net> wrote:
> 
>> What I'm trying to do is adjust date-time stamped file names for date and
>> time errors. The software program collects through a period that roughly
>> coincides with night hours every day and according to the OS clock. It
>> sometimes happens that a user sets the clock to the wrong day or hour,
>> possibly both. Possibly even the month or year. I'm trying to allow a user
>> the opportunity to repair the problem. (Date-time stamp part of the name is
>> yyyymmdd_hhmmss.) Correcting the date needs to be done easily and
>> accurately. For example, if on August 25, he mistakenly sets the date to
>> July 25, and discovers this problem on the real Oct. 5, he should be able to
>> shift all dates from July 25 through Sept. 5 to Aug. 25 through early Oct.,
>> allowing for day oddities in a month during the period. (I hope I got those
>> dates right; otherwise, I think you get the idea. In other words, he needs
>> to shift about 40 days of data to the correct dates.)
> 
> ... all of which is absolutely nothing to do with your surprise at the
> result of whatever.plus(months=6).
Really? It opened new insights for me. The example above is not the only 
correction I need to deal with. Further, the author is likely to soon 
clarify some of the date rules in the tutorial that were not obvious or 
mentioned there.
> 
> So for some period from recorded date X to recorded date Y, the
> recorded dates of out of kilter by D days. X = Jul 25 2008, Y Sep 5
> 2008, and D is 31 (days from Jul 25 to Aug 25). All you have to do is
> (pseudocode):
> 
> if X <= recorded_date <= Y:
>     new_recorded_date  = recorded_date.plus(days=D)
> 
> HTH,
> John
> 


-- 
                                    W. Watson
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