Not just datetime but any “embed values”: numbers (percents, currencies) and references too. Those have to be converted .ToText() before styling can be applied.
Not at the PC right now, will update sharing settings later. I’m using this trick a lot in my Best Practices Showcase though. Such a ubiquitous solution nowadays, even Codans now use it casually.
Also — not just Big Cell anymore, you can use Canvas columns as templates with extra formatting (namely columns). See my POS interface here:
Prefab Production Doc - YouTube (at about 1:20:00)