Time is expressed as seconds since some arbitrary time in the past; it is not correlated in any way to the time of day, and thus is not subject to resetting or drifting. The hi-res timer is ideally suited to performance measurement tasks, where cheap, accurate interval timing is required.
Examples
hires_time()
#> [1] 1737067568
# R rounds doubles to 7 digits by default, see greater precision by setting
# the digits argument when printing
print(hires_time(), digits = 20)
#> [1] 1737067567.5808773041
# Generally used by recording two times and then subtracting them
start <- hires_time()
end <- hires_time()
elapsed <- end - start
elapsed
#> [1] 0.0003533363