Searching for tutorials on ambiguous Debian commands

[Richard Owlett <rowlett@cloud85.net>]

I'm looking for a tutorial covering
"cron(3tcl) cron" [.../tcllib/cron.3tcl.en.html]
NOT "CRON(8) System Manager's Manual" [.../cron/cron.8.en.html]

Neither DuckDuckGo nor Google gave acceptable references.
Many were references to cron(8) *NOT* cron(3tcl).

A website of interest updates data hourly.
There is an internal time stamp in the data.
There is a significant, but a to be determined, delay between the 
time-stamp and when the data is available on the web.

I want to do data captures at 1 minute intervals from 10 minutes before 
to 10 minutes after the top of the hour.

Suggestions?
TIA