[R] Date handling in R is hard to understand

[Carl Witthoft]

I agree w/ lubridate.    I also would like to mention that   "date handling" 
is amazingly difficult in ALL computer languages, not just R.  Take a stroll
through sites like thedailywtf.com to see how quickly people get into
tarpits full of thorns when trying to deal with leap years, weeks vs month
ends, etc.   



Bert Gunter wrote
> Have a look at the "lubridate" package. It claims to try to make
> dealing with dates easier.
> 
> 
> -- Bert
> 
> On Fri, Nov 8, 2013 at 11:41 AM, Alemu Tadesse <

> alemu.tadesse@

> > wrote:
>> Dear All,
>>
>> I usually work with time series data. The data may come in AM/PM date
>> format or on 24 hour time basis. R can not recognize the two differences
>> automatically - at least for me. I have to specifically tell R in which
>> time format the data is. It seems that Pandas knows how to handle date
>> without being told the format. The problem arises when I try to shift
>> time
>> by a certain time. Say adding 3600 to shift it forward, that case I have
>> to
>> use something like:
>> Measured_data$Date <- as.POSIXct(as.character(Measured_data$Date),
>> tz="",format = "%m/%d/%Y %I:%M %p")+3600
>> or Measured_data$Date <- as.POSIXct(as.character(Measured_data$Date),
>> tz="",format = "%m/%d/%Y %H:%M")+3600  depending on the format. The date
>> also attaches MDT or MST and so on. When merging two data frames  with
>> dates of different format that may create a problem (I think). When I get
>> data from excel it could be in any/random format and I needed to
>> customize
>> the date to use in R in one of the above formats. Any TIPS - for
>> automatic
>> processing with no need to specifically tell the data format ?
>>
>> Another problem I saw was that when using r bind to bind data frames, if
>> one column of one of the data frames is a character data (say for example
>> none - coming from mysql) format R doesn't know how to concatenate
>> numeric
>> column from the other data frame to it. I needed to change the numeric to
>> character and later after binding takes place I had to re-convert it to
>> numeric. But, this causes problem in an automated environment. Any
>> suggestion ?
>>
>> Thanks
>> Mihretu
>>
>>         [[alternative HTML version deleted]]
>>
>> ______________________________________________
>> 

> R-help@

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>> and provide commented, minimal, self-contained, reproducible code.
> 
> 
> 
> -- 
> 
> Bert Gunter
> Genentech Nonclinical Biostatistics
> 
> (650) 467-7374
> 
> ______________________________________________

> R-help@

>  mailing list
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide
> http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.





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