How to handle mixed precision dates using R as.POSIXct - r

Question

I have a list of a series of dates, with mixed precision. Most have the format "1930-02-06T10:00:00", but a few have the format "2130-02-06" which I want to treat as 2130-02-06T00:00:00.
When I use
df$date <- as.POSIXct(df$date,tz=Sys.timezone())
I lose times from the data because some of the datetimes are missing time. I can write a little conversion routine
fixDateTime <- function (s) {
if(nchar(s) == 10) {
return (paste(s, "00:00:00"));
} else {
return (str_replace(s,"T", " "));
}
}
and then do
df$DATET <- as.POSIXct(fixDateTime(df$date),tz=Sys.timezone())
But that doesn't work because fixDateTime is actually given an array and I don't know how to adapt for that. I'm not sure which way to try to solve this. (and I'm sure this shows how newbie I am to R)

Answer 1

You can work with your fixDateTime function if you use ifelse which can handle vectors instead of if/else which works for scalars. Keeping everything in base R, we can do
fixDateTime <- function (s) {
ifelse(nchar(s) == 10, paste(s, "00:00:00"), sub("T", " ", s))
}
and then use it in as.POSIXct
as.POSIXct(fixDateTime(x), tz = "UTC")
#[1] "1930-02-06 10:00:00 UTC" "2130-02-06 00:00:00 UTC"
data
x <- c("1930-02-06T10:00:00", "2130-02-06")

Answer 2

Turns out lubridate is all you need:
library(lubridate)
data <- c("1930-02-06T10:00:00", "2130-02-06")
ymd_hms(data, truncated = 3)
#> [1] "1930-02-06 10:00:00 UTC" "2130-02-06 00:00:00 UTC"
Created on 2019-11-15 by the reprex package (v0.3.0)

Answer 3

#Ronak's answer is good as it uses just base R. Another solution is offered by the anytime() function of the anytime -- it does not need any formats.
R> library(anytime)
R> anytime(c("1930-02-06T10:00:00", "2130-02-06")) # localtime by default
[1] "1930-02-06 10:00:00 CST" "2130-02-06 00:00:00 CST"
R> anytime(c("1930-02-06T10:00:00", "2130-02-06"), tz="UTC", asUTC=TRUE) #override
[1] "1930-02-06 10:00:00 UTC" "2130-02-06 00:00:00 UTC"
R>
So you can have it as UTC, or in your local time.
The main key is that not giving hours:minutes:seconds is generally seen as midnight when you parse to datetime rather than date. So you may not need a helper function