IOS – Can Siri add some form of timestamp to a Note

I'd like Siri to add a timestamp — I'm not too fussy about the exact format — of the current day and time to the end of one of my notes in the Notes app. She can find the note just fine, but takes me too literally:

"Add the current date and time to my UFO Sightings note"

Okay, I updated your note:

UFO Sightings
Jun 3 11:18
Jun 5 11:28
The current date and time

In hopes of getting some guidance, I then tried

"Can you add a timestamp to one of my notes?"

She asked which one, and when I told her, she cheerfully replied

Okay, I updated your note:

UFO Sightings
Jun 3 11:18
Jun 5 11:28
The current date and time
A timestamp

I asked about her capabilities in general, too, and got a list of example commands, but it didn't seem exhaustive at all:

Is there a command I haven't been able to find? I'm willing to use this as an excuse to finally buy TextExpander (or similar) if necessary, though I'd prefer a built-in method.

I'm on an iPhone 5s running iOS 8.3.