[R] Mixed Date Formats

[Sarah Goslee]

On Thu, Jul 30, 2015 at 9:14 AM, John Kane <jrkrideau at inbox.com> wrote:
> This does not look good. But not too bad
>
> Can we assume that the original data is in D-M-Y in all cases. The values at 3 & 4 in the sample data are ambigous, in that someone may be using the American dating system of M-D-Y.  Given the rest of the data it seems unlikely but possible.

Take a look at 5 and 7:
>   5  1375 31/12/2011 # dd/mm/yyyy
>   7  3423 01/22/2011 # mm/dd/yyyy

They're unambiguously different.

> Otherwise it looks possible, but probably not for me since I'm lousy at things like grep, to sort the data set into three parts based on the last three characters in the Year part of the date, convert and recombine.

It would be easy if month and day were consistent, regardless of year format.


> SampleData
>   id value       date
>   1  5813  19-Dec-11
>   2  8706  07-Dec-11
>   3  4049   06/05/11
>   4  5877   05/12/11
>   5  1375 31/12/2011
>   6  2223 10/19/2011
>   7  3423 01/22/2011
>
> John Kane
> Kingston ON Canada
>
>
>> -----Original Message-----
>> From: r-help at r-project.org
>> Sent: Wed, 29 Jul 2015 21:15:45 +0000 (UTC)
>> To: sarah.goslee at gmail.com
>> Subject: Re: [R] Mixed Date Formats
>>
>> Hi Sarah,
>> Thanks for getting back to me.Here is an example of my data:SampleData <-
>> structure(list(id = 1:7, value = c(5813L, 8706L, 4049L, 5877L,
>> 1375L, 2223L, 3423L), date = structure(c(4L, 3L, 2L, 1L, 7L,
>> 6L, 5L), .Label = c("05/12/11", "06/05/11", "07-Dec-11",
>> "19-Dec-11", "01/22/2011", "10/19/2011", "31/12/2011"
>> ), class = "factor")), .Names = c("id", "value", "date"), row.names =
>> c(NA,
>> -7L), class = "data.frame")SampleData
>> Thanks for your help:).
>>
>>
>>
>>
>>      On Wednesday, July 29, 2015 1:50 PM, Sarah Goslee
>> <sarah.goslee at gmail.com> wrote:
>>
>>
>>  On Wed, Jul 29, 2015 at 2:45 PM, farnoosh sheikhi via R-help
>> <r-help at r-project.org> wrote:
>> >  Hi Arun,
>>> Hope all is well with you. I have a data with a column for date.The date
>>> format is mixed. There are date values with Month/Day/Year format and
>>> values with Day/Month/Year format.I don't know how to unify it.I really
>>> appreciate your help.Thanks.
>>
>> You sent this to the R-help list, not just to Arun, so I'm assuming
>> this is an R question. The best way to get help is to provide a sample
>> of your data using dput() and to clearly specify what you would like
>> as the result - "unify" is a bit vague. paste(x, collapse="") could be
>> considered unification, after all.
>>
>> Sarah
>>
>> --
>> Sarah Goslee
>> http://www.functionaldiversity.org
>>
>>
>



-- 
Sarah Goslee
http://www.functionaldiversity.org