Fix timezone-reliance in LastUpdated

[tmcw]

Description

• Closes lastUpdated displays incorrect date #1166
• This fixes an issue in which LastUpdated was server-rendered using the server's timezone, yielding incorrect dates.

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🦋 Changeset detected

Latest commit: 2218038

The changes in this PR will be included in the next version bump.

This PR includes changesets to release 1 package

Name	Type
@astrojs/starlight	Patch

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Name	Status	Preview	Updated (UTC)
starlight	✅ Ready (Inspect)	Visit Preview	Dec 6, 2023 6:31pm

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[kevinzunigacuellar]

LGTM!

Edit: The only thing that is missing is a changeset 👍

[tmcw]

👍 Added a changeset.

[delucis]

Thanks for the PR @tmcw! And sorry it got buried as we were prepping for Astro v4 and migrating Astro’s Docs to run on Starlight.

Have we tested this works as expected with git-based last updated times as well?

The updated date can come from git or from frontmatter, so ideally it would be great to handle here:

starlight/packages/starlight/utils/route-data.ts

Lines 72 to 84 in 7526059

	function getLastUpdated({ entry }: PageProps): Date | undefined {
	if (entry.data.lastUpdated ?? config.lastUpdated) {
	const currentFilePath = fileURLToPath(new URL('src/content/docs/' + entry.id, project.root));
	let date = typeof entry.data.lastUpdated !== 'boolean' ? entry.data.lastUpdated : undefined;
	if (!date) {
	try {
	({ date } = getFileCommitDate(currentFilePath, 'newest'));
	} catch {}
	}
	return date;
	}
	return;
	}

This would also mean anyone overriding this component would get the correct behaviour without having to replicate this logic. May not be possible though given we’re providing a Date object in route data.

[kevinzunigacuellar]

I don't think that the issue is that the Date object is wrong. It just displays the wrong time when its converted to a string because it adjusts to the local timezone. I fear that changing the date object upstream might result in unexpected date behavior for users.

[delucis]

Yeah, you’re probably right @kevinzunigacuellar! Let’s give it a try and if anyone notices broken behaviour with this change, hopefully they’ll let us know — thanks again @tmcw 🙌