When the micro:bit is powered the vibration motor will vibrate for 1 second and then stop for 1 second. At the same time as the vibration the LED matrix will light up for the same period of time and will turn when the vibration motor turns off. This will repeat 4 times.
After the 4 repetitions the micro:bit will begin a countdown of 30 minutes. After 30 minutes the code will restart and the vibration motor and LED matrix will again vibrate and light up 4 times.
This code is in a forever loop so will continue whilst the micro:bit is powered.