sS ymdWithSlashes() {
  ret ymdWithSlashes(now());
}

sS ymdWithSlashes(long time) {
  ret simpleDateFormat_local("YYYY/MM/dd").format(time);
}

sS ymdWithSlashes(long time, TimeZone tz) {
  ret simpleDateFormat("YYYY/MM/dd", tz).format(time);
}