[R] excel dates and times in R

[(Ted Harding)]

On 05-Aug-11 10:27:28, bevare wrote:
> Hello,
> I am having some fun dealing with dates and times. My input
> is a excel csv file with two columns with data in the following
> format: 
> 
> date                                   time
> 25-Jun-1961                       04:00:00
> 
> i.e. day - month - year       hour:min:sec
> 
> I would like to have a single object in R that combines these
> and converts them into a sensible R format (e.g.
> ISOdatetime(1961,06,25,04,00,00,tz="GMT").
> 
> I have played with the function chron and also strptime but
> can't seem to get them to work. 
> 
> Can anybody help me out please? 
> 
> Thanks
> Bevare

I know almost nothing about using the "time" functions in R,
but since I see that I get:

  ISOdatetime(1961,06,25,04,00,00,tz="GMT")
  # [1] "1961-06-25 04:00:00 GMT"

it would seem that you already have it almost made in the
original Excel fields, namely:

  paste("1961-06-25","04:00:00","GMT",sep=" ")
  # [1] "1961-06-25 04:00:00 GMT"

So you could write this as a function

  getISOdt <- function(date,time,zone){
    paste(date,time,zone,sep=" ")
  }

where the parameters date, time and zone are supplied as
character strings:

  getISOdt("1961-06-25","04:00:00","GMT")
  [1] "1961-06-25 04:00:00 GMT"

Then you can apply() this to the two comlumns in the dataframe
you get when reading in the Excel CSV file, with zone being
supplied independently.

Hoping this helps,
Ted.

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Date: 05-Aug-11                                       Time: 13:59:14
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