Hi Not sure why the date format was changed but if I am correct R do not read dates as dates but as character vector. You need to transfer such columns to dates by asDate. The error is probably from your use two asDate commands.
Cheers Petr -----Original Message----- From: R-help <r-help-boun...@r-project.org> On Behalf Of Val Sent: Thursday, November 4, 2021 10:43 PM To: r-help@R-project.org (r-help@r-project.org) <r-help@r-project.org> Subject: [R] Date IHi All, l, I am reading a csv file and one of the columns is named as "mydate" with this form, 2019-09-16. I am reading this file as dat=read.csv("myfile.csv") the structure of the data looks like as follow str(dat) mydate : chr "09/16/2019" "02/21/2021" "02/22/2021" "10/11/2017" ... Please note the format has changed from YYYY-mm-dd to mm/dd/YYYY When I tried to change this as a Date using as.Date(as.Date(mydate, format="%m/%d/%Y" ) I am getting this error message Error in charToDate(x) : characte string is not in a standard unambiguous format My question is, 1. how can I read the file as it is (i.e., without changing the date format) ? 2. why does R change the date format? Thank you, ______________________________________________ R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see 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. Osobní údaje: Informace o zpracování a ochraně osobních údajů obchodních partnerů PRECHEZA a.s. jsou zveřejněny na: https://www.precheza.cz/zasady-ochrany-osobnich-udaju/ | Information about processing and protection of business partner’s personal data are available on website: https://www.precheza.cz/en/personal-data-protection-principles/ Důvěrnost: Tento e-mail a jakékoliv k němu připojené dokumenty jsou důvěrné a podléhají tomuto právně závaznému prohláąení o vyloučení odpovědnosti: https://www.precheza.cz/01-dovetek/ | This email and any documents attached to it may be confidential and are subject to the legally binding disclaimer: https://www.precheza.cz/en/01-disclaimer/ ______________________________________________ R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see 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.