"XLConnect" packages; Excel dates read incorrectly

date11

Hi,

   Thank you for all your responses.
   For Eric, The files are attached. (I believe it was also attached in my
first message)
   For David, Could you send me the link regarding possible solutions or a
more comprehensive description of the problem?

   Thanks,

John


2017-09-23 22:29 GMT-07:00 David Winsemius <dwinsemius at comcast.net>:

On Sep 23, 2017, at 6:30 AM, Eric Berger <ericjberger at gmail.com> wrote:

Jim,
I don't see how that link could be related to John's issue. Symptoms
related to your link involve discrepancies of four years whereas John is
seeing discrepancies of one day.

The MS Excel starting point was off by one day. R does not repeat that
error. MS claims that their  error is justified by needing to copy the
error made by Lotus123 and then because they wanted backward compatibility.

I'm not sure why the XLConnect package does not fix the error. They just
use the integer from Excel and let R apply it correctly.
--
David.

John,
I do not see any attached files.

Regards

On Sat, Sep 23, 2017 at 1:30 PM, Jim Lemon <drjimlemon at gmail.com>

wrote:

Hi John,
It could be due to this:

https://support.microsoft.com/en-au/help/214330/differences-
between-the-1900-and-the-1904-date-system-in-excel

Jim


On Sat, Sep 23, 2017 at 1:04 PM, John <miaojpm at gmail.com> wrote:

Hi,

  I tried to read xlsx files by "XLConnect" packages, but the dates

are

one day earlier than it is supposed to be. I moved from California to
Taiwan (Eastern Asia), and it worked well in California, but not in

Taiwan.

Even if I adjust my Mac time to California time zone, it gives the

wrong

dates. I don't know which part of the setting (in RStudio or in my

Mac?)

I

should adjust. The codes and the data are attached.

  My data are on weekdays, Monday to Friday every week, but they are

read

as Sunday to Thursday.

Data:
2004-01-01 (Th)
2004-01-02 (F)
2004-01-05 (M)
2004-01-06 (T)
2004-01-07 (W)
2004-01-08 (Th)
2004-01-09 (F)

The data are read as:
"2003-12-31" (W)
"2004-01-01" (Th)
"2004-01-04" (Su)
"2004-01-05" (M)
"2004-01-06" (Tu)
"2004-01-07" (W)
"2004-01-08" (Th)



The codes are (also attached):


rm(list=ls())
library(XLConnect)
library(xlsx)

fl<-paste("allData_out3.xlsx")
a1<-readWorksheetFromFile(fl, sheet="first", colTypes="numeric")
b1<-readWorksheetFromFile(fl, sheet="second", colTypes="numeric")
a_col<-readWorksheetFromFile(fl, sheet="first")
date11<-as.Date(a_col$date, format="%Y-%m-%d")


The output:

date11

[1] "2003-12-31" "2004-01-01" "2004-01-04" "2004-01-05" "2004-01-06"
"2004-01-07"
[7] "2004-01-08" "2004-01-11" "2004-01-12" "2004-01-13" "2004-01-14"
"2004-01-15"
[13] "2004-01-18" "2004-01-19" "2004-01-20" "2004-01-21" "2004-01-22"
"2004-01-25"
[19] "2004-01-26" "2004-01-27" "2004-01-28" "2004-01-29" "2004-02-01"

Thanks!!

posting-guide.html

      [[alternative HTML version deleted]]

ng-guide.html

David Winsemius
Alameda, CA, USA

'Any technology distinguishable from magic is insufficiently advanced.'
 -Gehm's Corollary to Clarke's Third Law