In the example above code line delay (86400000); and delays (3600000); find output time intervals ON and OFF OFF respectively, in milliseconds. Here, a total of 86400000 milliseconds corresponds to 24 hours, while 3600000 shows a 1 hour delay.
You can customize these two numbers as your preference to get the necessary delays.
Once set and enabled, Arduino will continue to switch between the two steps on / off in sequence. as long as the power is still active in the system.