I can't figure out how to set up a custom date that takes data from 16:00 to 15:59 eg.
I can only choose today, yesterday and so on.
Is there any fix for this?
So for Data Studio your only possible tool for this is filtering with regex expressions on the time based fields. You don't get the custom dates or the time formatting you can do in Sheets. Not all data sources will give a time stamp (though perhaps can have their display settings changed to expose it) and not all will work with this.
So some experimentation is needed.
In Facebook Ads, there's a hour dimension by default, which is convenient. So I can build a really simple regex to get the first two hours (not elegant but shows the point).
And the apply that to my table:
So I hope this gives you some ideas.