Date: Thu, 11 May 2006 05:33:53 -0500
Reply-To: Jeffrey Berman <jberman@memphis.edu>
Sender: "SPSSX(r) Discussion" <SPSSX-L@LISTSERV.UGA.EDU>
From: Jeffrey Berman <jberman@memphis.edu>
Subject: Re: Compute statement involving dates
In-Reply-To: <200605110400.k4AN02So006812@malibu.cc.uga.edu>
Content-type: text/plain; charset="ISO-8859-1"
On 5/10/06 8:16 AM, "Beadle, ViAnn" <viann@spss.com> wrote:
> Sorry, I don't know about any differences between Excel on the Mac and Excel
> on the PC WRT dates. I do know that Excel's base date is January 1, 1900 and
> SPSS seems to resolve that OK.
>
> -----Original Message-----
> From: Ian Martin [mailto:ianmartin@mac.com]
> Sent: Wednesday, May 10, 2006 8:01 AM
> To: SPSSX (r) Discussion; Beadle, ViAnn
> Subject: Re: Compute statement involving dates
>
> ViAnn,
>
> How does SPSS handle the 4-year difference in dates as coded by
> excel:mac and excel:pc? I have run afoul of this "feature" in excel
> when moving date variables from one platform to another, all within
> excel.
ViAnn and Ian:
On a Macintosh version of Excel, the default date system is set to use
January 1, 1904, as the base date, whereas the Windows version uses January,
1, *1900*. However, one can change the base date in the Macintosh version
of Excel using the checkbox found in the Calculation pane of Preferences
(Excel -> Preferences... -> Calculation -> 1904 date system).
Relevant information about this issue from Excel help is attached below.
Unfortunately, the date conversion from Excel to SPSS on a Macintosh seems
to be off whether one uses the 1904 or 1900 date system. For instance, I
created an Excel file using the default 1904 system and another Excel file
using the 1900 system. Below are the conversions of a date variable when
each Excel file was opened as data using the current release of SPSS for the
Macintosh (v. 11.0.4):
Date system: 1904
Excel date variable: 5/11/06 4:57 AM
SPSS date variable: 10-MAY-2006 04:57
Date system: 1900
Excel date variable: 5/11/06 4:58 AM
SPSS date variable: 12-MAY-2006 04:58
Note that the year and time are correct, but the day is off in both cases.
-Jeffrey Berman
----- Attachment follows -----
€ Microsoft Excel for Windows and Microsoft Excel for the Macintosh use
different default date systems. Microsoft Excel for Windows uses the 1900
date system, in which serial numbers correspond to the dates January 1,
1900, through December 31, 9999. Excel for the Macintosh uses the 1904 date
system, in which serial numbers correspond to the dates January 1, 1904,
through December 31, 9999.
€ Numbers to the right of the decimal point in the serial number represent
the time; numbers to the left represent the date. For example, in the 1900
date system, the serial number 367.5 represents the date-time combination
12:00 P.M., January 1, 1901.
€ You can change the date system to the 1900 system by clearing the 1904
date system check box in Calculation in the Preferences dialog box (Excel
menu). The 1904 date system is the default setting in Excel for the
Macintosh.
€ The date system is changed automatically when you open a document from
another platform. For example, if you are working in Excel for Windows and
you open a document created in Excel for the Macintosh, the 1904 date system
check box is selected automatically.
----- End of attachment -----
