PERIODIC(8) man page:
The periodic utility is intended to be called by cron(8) to execute shell scripts located in the specified directory.
One or more of the following arguments must be specified:
daily Perform the standard daily periodic executable run. This usu- ally occurs early in the morning (local time). weekly Perform the standard weekly periodic executable run. This usu- ally occurs very early on Saturday mornings.
Why does it say for weekly, for example, that it "usually occurs very early on Saturday mornings?" Is it suggesting that the user set the cron-job for
periodic weekly to be "very early on Saturday mornings?"