Datetime formatting changed from Node v16.16.0 to v16.17.0 but can't find changelog entry

[noahnu]

In node v16.17.0, a change was introduced which causes different datetime formatting when using Date.prototype.toLocaleDateString.

In Node v16.16.0, executing:

node -e "console.log(new Date().toLocaleDateString('en-US', {weekday:'long', year:'numeric', month:'long', day: 'numeric', hour: 'numeric', minute: 'numeric'}))"

produces:

Thursday, October 13, 2022, 10:09 AM

while in Node v16.17.0 we get:

Thursday, October 13, 2022 at 10:09 AM

Note the comma before the timestamp changes to the word "at".

I'm fine with this change, just trying to understand why it was introduced. I can't seem to find any relevant commits or notes in the changelog: https://github.com/nodejs/node/blob/main/doc/changelogs/CHANGELOG_V16.md?plain=1. Could anyone with a better understanding of the node project point me to the commit/issue/discussion?

[richardlau]

It's the ICU update (to 71.1). See #44454 for discussion.