Crie um script com a seguinte contestação
#!/bin/bash
first_u=$(awk '{printf "%.0f" , $0/60;}' /proc/uptime)
while true
do
uptime_m=$(awk '{printf "%.0f" , $0/60;}' /proc/uptime)
(( time_dif=$uptime_m - $first_u ))
if [ $time_dif -eq 30 ]; then
notify-send "You have on laptop since 30 minutes"
sleep 1800
notify-send "You have on laptop since 1 hour"
sleep 1800
notify-send "You have on laptop since 1:30 hour"
sleep 1800
notify-send "You have on laptop since 2 hour"
break
fi
sleep 50
done
Salve e torne-o executável usando
chmod a+x <script_name>
Agora execute-o
./<script_name>