How to preserve decimal values when converting POSIXct to character?

Question

> t <- Sys.time()
> ct <- as.character(t)
> t - as.POSIXct(ct)
Time difference of 0.4370408 secs

The above example indicates that precision is lost when converting POSIXct to character.

How to preserve the exact value when converting to character so that when I convert back to POSIXct from character I get the original value?

It is often wise to give your objects not the same name as a function; see `?t`. — Jaap, Jun 23 '21 at 12:49

score 4 · Answer 1 · answered Jun 23 '21 at 12:46

4

You can set the option digits.secs to 6 (its maximum value).

options(digits.secs = 6)

t <- Sys.time()
ct <- as.character(t)
t - as.POSIXct(ct)

Time difference of 0 secs

answered Jun 23 '21 at 12:46

ktiu

Is there a way to do it without having to mess with the global options? – Bear Bile Farming is Torture Jun 23 '21 at 13:27

score 2 · Answer 2 · answered Jun 23 '21 at 15:05

2

You can use format with %OS6, to give seconds in digits, but still there will be sometimes a difference:

t <- Sys.time()
ct <- format(t, "%Y-%m-%d %H:%M:%OS6")
t - as.POSIXct(ct)
#Time difference of 0 secs

answered Jun 23 '21 at 15:05

GKi

2 Answers2