Good Day,
I tend to avoid cron job on the control system since I don't know that it is *guaranteed* to run, and at specified time - though it usually does. Even though crontab is a great tool, it isn't a control system tool, so
my preference is to avoid it (except for say, booting a control system).
I implemented a calc record that uses inputs from the devIocStats (synapps) to get the second, minute, and hour, and compare them with your desired values and make the Val=1 if equal, which is essentially what you want.
If you connect that to the SDIS of a fanout and process the fanout every 1/2 second then you will get a single process signal output, at the time of day you specify (because usually it's disabled).
You can do the same thing but only use seconds, and minutes for something that happens every hour, and likewise for month and day. Sometimes I want to process a record, but only once every 10 minutes.
Cheers
James Larsson