Execute a function every x minutes

In WordPress, and without additional tools, how can I execute a function every x minutes?

I want to import new posts from another website programmaticaly (namely videos from a YouTube account)开发者_Python百科, and I don't want to execute all the required checks on every pageload.

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I don't know WordPress that well, or how you are importing the new posts. But could you combine an HTML ( refresh ), and a javascript onRefresh() function?