R Under development (unstable) (2024-11-21 r87357) -- "Unsuffered Consequences" Copyright (C) 2024 The R Foundation for Statistical Computing Platform: aarch64-apple-darwin23.6.0 R is free software and comes with ABSOLUTELY NO WARRANTY. You are welcome to redistribute it under certain conditions. Type 'license()' or 'licence()' for distribution details. R is a collaborative project with many contributors. Type 'contributors()' for more information and 'citation()' on how to cite R or R packages in publications. Type 'demo()' for some demos, 'help()' for on-line help, or 'help.start()' for an HTML browser interface to help. Type 'q()' to quit R. > #### Test R's (64-bit) date-time functions .. output tested *sloppily* > > ## R's internal fixes are used on 32-bit platforms. > ## macOS gets these wrong: see HAVE_WORKING_64BIT_MKTIME > > Sys.setenv(TZ = "UTC") > (z <- as.POSIXct("1848-01-01 12:00")) [1] "1848-01-01 12:00:00 UTC" > c(unclass(z)) [1] -3849940800 > (z <- as.POSIXct("2040-01-01 12:00")) [1] "2040-01-01 12:00:00 UTC" > c(unclass(z)) [1] 2209032000 > (z <- as.POSIXct("2040-07-01 12:00")) [1] "2040-07-01 12:00:00 UTC" > c(unclass(z)) [1] 2224756800 > > Sys.setenv(TZ = "Europe/London") # pretty much portable. > (z <- as.POSIXct("1848-01-01 12:00")) [1] "1848-01-01 12:00:00 GMT" > c(unclass(z)) [1] -3849940800 > ## We don't know the operation of timezones next year let alone in 2040 > ## but these should at least round-trip > ## These got the wrong timezone on Linux with glibc 2.2[67] > as.POSIXct("2040-01-01 12:00") [1] "2040-01-01 12:00:00 GMT" > as.POSIXct("2040-07-01 12:00") [1] "2040-07-01 12:00:00 BST" > > Sys.setenv(TZ = "EST5EDT") # also pretty much portable. > ## However, tzdata 2024b changed this from EST to LMT (and by 238s) > ## IGNORE_RDIFF_BEGIN > (z <- as.POSIXct("1848-01-01 12:00")) [1] "1848-01-01 12:00:00 LMT" > c(unclass(z)) [1] -3849923038 > ## IGNORE_RDIFF_END > ## see comment above > as.POSIXct("2040-01-01 12:00") [1] "2040-01-01 12:00:00 EST" > as.POSIXct("2040-07-01 12:00") [1] "2040-07-01 12:00:00 EDT" > > ## PR15613: had day as > 24hrs. > as.POSIXlt(ISOdate(2071,1,13,0,0,tz="Etc/GMT-1"))$wday [1] 2 > as.POSIXlt(ISOdate(2071,1,13,0,1,tz="Etc/GMT-1"))$wday [1] 2 > > > ## Incorrect use of %b should work even though abbreviation does match > Sys.setlocale("LC_TIME", "C") # to be sure [1] "C" > stopifnot(!is.na(strptime("11-August-1903", "%d-%b-%Y"))) > > ## Prior to R 4.0.0 this overflowed an array. Now gives a warning > > z <- paste("2017", c(1,365,366), sep = "-") > (zz <- strptime(z, "%Y-%j")) [1] "2017-01-01 EST" "2017-12-31 EST" NA Warning message: In strptime(z, "%Y-%j") : day-of-year 366 in year 2017 is invalid > stopifnot(identical(is.na(zz), c(FALSE, FALSE, TRUE))) >