Re: [R] Create previous dates from date with consideration of leap year

Here is an example of converting the 'date' your dataframe to 'time' (POSIXct) and then taking the first 'time' and creating the 5 previous days from that date: id date case 1 1 27apr19931 2 2 13feb20051 3 3 29may20021 4 4 22sep20051 5 5 18dec19911 6 6 07jun

Re: [R] Create previous dates from date with consideration of leap year

The sample data you provided has the variable 'date'. Since the type of this variable is 'factor', you may try to convert type of variable from 'factor' to 'date' as shown in the below: > x$rval <- as.Date(x$date, format="%d%b%Y")-5 > x id date case rval 1 1 27apr19931 1993

[R] Create previous dates from date with consideration of leap year

Dear R Community, I wish to create 5 preceding dates from the date variable by ID. How could I create such dates? The code should consider leap year. Thanks Sample data follows: structure(list(id = 1:12, date = structure(c(9L, 6L, 11L, 8L, 7L, 5L, 4L, 3L, 12L, 1L, 10L, 2L), .Label = c("01feb20