path <- "C:/Users/James/Desktop/stihtians_mapir/photo_sub"

files <- list.files(path)

for(i in 1:length(files)) {
  system(paste0("C:/exiftool/exiftool.exe ", "-overwrite_original -alldates+=\"1:0:0 0\" ", path,
                "/",files[i]))
}

#in alldates+= \ are used to escape "
#in alldates+= "Y:M:D 0" is the syntax. Trailing 0 stays.