# File rbot/plugins/remind.rb, line 23
  def add_reminder(who, subject, timestr, repeat=false)
    begin
      period = Irc::Utils.timestr_offset(timestr)
    rescue RuntimeError
      return "couldn't parse that time string (#{timestr}) :("
    end
    if(period <= 0)
      return "that time is in the past! (#{timestr})"
    end
    if(period < 30 && repeat)
      return "repeats of less than 30 seconds are forbidden"
    end
    if(!@reminders.has_key?(who))
      @reminders[who] = Hash.new
    elsif(@reminders[who].has_key?(subject))
      del_reminder(who, subject)
    end
    
    if(repeat)
      @reminders[who][subject] = @bot.timer.add(period) {
        time = Time.now + period
        tstr = time.strftime("%H:%M:%S")
        @bot.say who, "repeat reminder (next at #{tstr}): #{subject}"
      }
    else
      @reminders[who][subject] = @bot.timer.add_once(period) {
        time = Time.now + period
        tstr = time.strftime("%H:%M:%S")
        @bot.say who, "reminder (#{tstr}): #{subject}"
      }
    end
    return false
  end