On iOS, how can I insert a date/time stamp while I'm writing something?
Sadly, the Shortcuts app is one item short of doing this pretty much natively.

It has a text function that pastes in the value of the current date, but there isn’t ISO formatting option.

I tried a Pythonista script that works very well to get the values you need, just am missing some glue to turn it into a shortcut.

import datetime
iso = datetime.date.today().isoformat()
print(iso)




Siri can even trigger this shortcut (or share sheet) for you, once I figure out how to get the two connected.