R, how to get current time miliseconds, without extra information ? (Sys.time(), format("%X"))

I have tried to get just the current miliseconds from the current second in R with the following code:

options("digits.secs" = 6) # since 6 is the maximum digits for seconds apparently

Sys.time()

So, it returns the full date with the miliseconds.

2024-10-09 14:35:51.687084 CEST

But if i just want to have the miliseconds what should i do with format() ?

I have tried,

options(digits.secs = 6)

format(Sys.time(), "%X")

But it only returns the following:

14:35:51

I just want it to return 687084

I know i can do the following but it does not look optimal:

options("digits.secs" = 6)
unlist(strsplit(x = as.character(Sys.time()), split = "\\."))[2]

Do you have any idea how to do it?

Thanks.

No format will give the seconds' decimal part, you have to extract from the value representing a date/time. In R, objects of class "POSIXct" are represented as numbers.

Two ways.

1. Use base function substring to extract the decimal digits as characters;
2. Use modular arithmetic.

secs_decimal1 <- function(x) {
  if(missing(x)) x <- Sys.time()
  substring(x, 21L)
}
secs_decimal2 <- function(x) {
  if(missing(x)) x <- Sys.time()
  unclass(x) %% 1L
}

# save the current setting
op <- options("digits.secs" = 6)

x <- Sys.time()
secs_decimal1(x)
#> [1] "344074"
secs_decimal2(x)
#> [1] 0.344074
options(op)

^{Created on 2024-10-09 with reprex v2.1.0}