Hi, You could try this: library(lubridate) res<-as.Date(dmy(format(Date-8, "%d-%m-%Y"))+months(Vec)) res #[1] "2013-03-01" "2014-04-01" "2014-01-01" "2013-07-01" A.K.
----- Original Message ----- From: Christofer Bogaso <bogaso.christo...@gmail.com> To: r-help <r-help@r-project.org> Cc: Sent: Saturday, March 9, 2013 6:41 AM Subject: [R] Calculation with date Hello again, Let say I have an non-negative integer vector (which may be random): Vec <- c(0, 13, 10, 4) And I have a date: > Date <- as.Date(Sys.time()) > Date [1] "2013-03-09" Using these 2 information, I want to get following date-vector: New_Vec <- c("2013-03-01", "2014-04-01", "2014-01-01", "2013-07-01") Basically the month-difference between 'New_Vec' and 'Date' will be 'Vec ' Is there any R function to do it programmatically? Thanks for your help. ______________________________________________ R-help@r-project.org 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. ______________________________________________ R-help@r-project.org 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.