The formatTimeString util will return string values that bypass i18n (now, Invalid Date).
Investigate how best to incorporate i18n.

I'd like to see this use i18n, but none of the other values from this function use it and it's unclear how we'd adjust the output.

I'll open a separate issue to explore; this doesn't need to be a blocker for this PR.

Originally posted by @thompsongl in #5263 (comment)