R incorrect value of date function

Question

I'm trying to use as.Date in R.

I'm using the command:

as.Date("65-05-14", "%y-%m-%d")

I get:

"2065-05-14"

Is there any way to get it show 1965 instead? Or do I need to recode everything into long format -- eg add 1900 as a numeric?

Thanks!

Answer 1

I didn't see this simple solution in the linked questions, so I'm adding it here too.

In base R you can simply use as.POSIXlt class which provides year attribute. You can then simply reduce 100 years.

Lets say this is your dates vector

(Date <- c("65-05-14", "15-05-14", "25-05-14", "34-05-14"))
## [1] "65-05-14" "15-05-14" "25-05-14" "34-05-14"

You can simply do

Date <- as.POSIXlt(Date, format = "%y-%m-%d")
Date$year <- Date$year - 100L
Date # Alternatively, you could also do `as.Date(Date)`
## [1] "1965-05-14 IDT" "1915-05-14 IDT" "1925-05-14 IDT" "1934-05-14 IDT"