A common process when data is obtained in an Excel spreadsheet is to save the spreadsheet as a .csv file then read it into R. Experienced users might have learned to be wary of dates (as I have) but possibly have not experienced what just happened to me. I thought I might just share it with r-help as a cautionary tale.
I received an Excel file giving patient details. Each patient had an ID code in the form of three letters followed by four digits. (Actually a New Zealand National Health Identification.) I saved the .xls file as .csv. Then I opened up the .csv (with Excel) to look at it. In the column of ID codes I saw: Aug-99. Clicking on that entry it showed 1/08/2699. In a column of character data, Excel had interpreted AUG2699 as a date. The .csv did not actually have a date in that cell, but if I had saved the .csv file it would have. David Scott _________________________________________________________________ David Scott Department of Statistics, Tamaki Campus The University of Auckland, PB 92019 Auckland 1142, NEW ZEALAND Phone: +64 9 373 7599 ext 86830 Fax: +64 9 373 7000 Email: [EMAIL PROTECTED] Graduate Officer, Department of Statistics Director of Consulting, Department of Statistics ______________________________________________ R-help@stat.math.ethz.ch 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.