when you have no atd, this is handy

poor_mans_at.sh

#!/bin/bash
# Basic bash implementation of at(1). Obviously doesn't survive a reboot.
poor_mans_at() { 
  delay=$[$(date +%s -d "$*") - $(date +%s)] 
  if [[ ! "$delay" -ge 0 ]]; then
    echo "error: invalid time specification" >&2
    return 1
  fi
  mapfile cmds 
  ( sleep $delay && eval "${cmds[@]}" )&disown
}