What is the best way to trigger an action at a certain time?

[Tim Selander]

Dear all,

I want to have an LC app running on a computer doing nothing but 
watching the time. At predetermined times, I then want it to run 
a command. A call to an API on a website.

In the old HC days, I remember using "on idle" to watch for a set 
time. But even then, using "on idle" was less than ideal. CPU 
hog. What is the preferred/LC way to have an app trigger a 
command at a specific time of day?

Any pointers appreciated!

Tim Selander
Tokyo, Japan