Cron is a utility for scheduling tasks to run on Linux and Unix systems. For example, you could run a script to scrape a website every Monday at 3 a.m. Or every third Monday. Or every four hours.
“What is Cron?” and other basic questions are answered clearly here.
“EasyCron” is a web-based cron manager. Starter plan: $12/month. Try it free for eight days.