Sys.setFileTime(path, time)
"POSIXct"
or an object which can
be coerced to one. Fractions of a second may be ignored.
utimensat
if that is
available, otherwise utimes
or utime
. On a POSIX file
system it sets both the last-access and modification times.
Fractional seconds will set as from R 3.4.0 on OSes with the
requisite system calls and suitable filesystems. On Windows it uses the system call SetFileTime
to set the
‘last write time’. Some Windows file systems only record the
time at a resolution of two seconds.