Google が正しい日付を選択できるように、サイト所有者とパブリッシャーは次のことを行ってください。
明確な日付を表示する: ページ上で目立つように日付を表示します。
構造化データを使用する:datePublished スキーマと dateModified スキーマを使用し、AMP ページまたは非 AMP ページ用の正しいタイムゾーン指定子を設定します。構造化データを使用する場合は、日付に ISO 8601 形式を使用してください。
Google ニュース固有のガイドライン
Google ニュースでは、コンテンツが公開または更新された時点の日付と時刻の両方を明確に表示する必要があります。日付と時刻の表示に加えて構造化データを使用することが推奨され、構造化データだけでは不十分です。日付と時刻は見出しと記事本文の間に配置してください。詳細なガイダンスについては、記事の日付に関するヘルプページをご覧ください。
[[["わかりやすい","easyToUnderstand","thumb-up"],["問題の解決に役立った","solvedMyProblem","thumb-up"],["その他","otherUp","thumb-up"]],[["必要な情報がない","missingTheInformationINeed","thumb-down"],["複雑すぎる / 手順が多すぎる","tooComplicatedTooManySteps","thumb-down"],["最新ではない","outOfDate","thumb-down"],["翻訳に関する問題","translationIssue","thumb-down"],["サンプル / コードに問題がある","samplesCodeIssue","thumb-down"],["その他","otherDown","thumb-down"]],[],[[["\u003cp\u003eGoogle uses a variety of signals, including on-page dates and structured data, to determine the date displayed in search results.\u003c/p\u003e\n"],["\u003cp\u003eTo improve date accuracy, website owners should display a clear date on the page and utilize structured data with the correct time zone.\u003c/p\u003e\n"],["\u003cp\u003eGoogle News requires both date and time to be clearly visible on the page, positioned between the headline and article text, in addition to structured data.\u003c/p\u003e\n"],["\u003cp\u003eWhen updating content, ensure the visible date is also updated, potentially showing both original and updated dates for clarity.\u003c/p\u003e\n"],["\u003cp\u003eAvoid using future dates, dates related to the page's topic, and ensure consistency in date and time usage across the page and structured data.\u003c/p\u003e\n"]]],["Google determines page dates for search results using multiple factors, including visible dates and structured data. Publishers should prominently display the publication or update date and use `datePublished` and `dateModified` schema in ISO 8601 format. For Google News, both visible date/time and structured data are required, positioned between the headline and content. Update dates when significantly changing content, avoid \"freshening\" without new information, use the correct timezone, and do not use dates linked to future events.\n"],null,["# Help Google Search know the best date for your web page\n\nMonday, March 11, 2019\n\n\nSometimes, Google shows dates next to listings in its search results. In this post, we'll answer\nsome commonly-asked questions webmasters have about how these dates are determined and provide\nsome best practices to help improve their accuracy.\n\nHow dates are determined\n------------------------\n\n\nGoogle shows the date of a page when its automated systems determine that it would be relevant to\ndo so, such as for pages that can be time-sensitive, including news content:\n\n\nGoogle determines a date using a variety of factors, including but not limited to: any prominent\ndate listed on the page itself or dates provided by the publisher through structured markup.\n\n\nGoogle doesn't depend on one single factor because all of them can be prone to issues. Publishers\nmay not always provide a clear visible date. Sometimes, structured data may be lacking or may not\nbe adjusted to the correct time zone. That's why our systems look at several factors to come up\nwith what we consider to be our best estimate of when a page was published or significantly\nupdated.\n\nHow to specify a date on a page\n-------------------------------\n\n\nTo help Google to pick the right date, site owners and publishers should:\n\n- **Show a clear date**: Show a visible date prominently on the page.\n- **Use structured data** : Use the `datePublished` and `dateModified` schema with the correct time zone designator for [AMP](/search/docs/appearance/structured-data/article#amp) or [non-AMP pages](/search/docs/appearance/structured-data/article#non-amp). When using structured data, make sure to use the [ISO 8601 format](https://en.wikipedia.org/wiki/ISO_8601) for dates.\n\nGuidelines specific to Google News\n----------------------------------\n\n\nGoogle News requires clearly showing both the date and the time that content was published or\nupdated. Structured data alone is not enough, though it is recommended to use in addition to a\nvisible date and time. Date and time should be positioned between the headline and the article\ntext. For more guidance, also see our\n[help page about article dates](https://support.google.com/news/publisher-center/answer/9607104).\n\n\nIf an article has been substantially changed, it can make sense to give it a fresh date and\ntime. However, don't artificially freshen a story without adding significant information or\nsome other compelling reason for the freshening. Also, do not create a very slightly updated\nstory from one previously published, then delete the old story and redirect to the new one.\nThat's against our\n[article URLs](https://support.google.com/news/publisher-center/answer/68323)\nguidelines.\n\nMore best practices for dates on web pages\n------------------------------------------\n\n\nIn addition to the most important requirements listed above, here are additional best practices\nto help Google determine the best page to consider showing for a web page:\n\n- **Show when a page has been updated** : If you update a page significantly, also update the visible date (and time, if you display that). If desired, you can show two dates: when a page was originally published and when it was updated. Just do so in a way that's visually clear to your readers. If showing both dates, it's also highly recommended to use `datePublished` and `dateModified` for [AMP](/search/docs/appearance/structured-data/article#amp) or [non-AMP pages](/search/docs/appearance/structured-data/article#non-amp) to make it easier for algorithms to recognize.\n- **Use the right time zone** : If specifying a time, make sure to provide the [correct timezone](https://en.wikipedia.org/wiki/ISO_8601#Time_zone_designators), taking into account [daylight saving time](https://en.wikipedia.org/wiki/Daylight_saving_time) as appropriate.\n- **Be consistent in usage**. Within a page, make sure to use exactly the same date (and, potentially, time) in structured data as well as in the visible part of the page. Make sure to use the same timezone if you specify one on the page.\n- **Don't use future dates or dates related to what a page is about** : Always use a date for when a page itself was published or updated, not a date linked to something like an event that the page is writing about, especially for events or other subjects that happen in the future (you may use [Event markup](/search/docs/appearance/structured-data/event) separately, if appropriate).\n- **Follow Google's structured data guidelines** : While Google doesn't guarantee that a date (or structured data in general) specified on a page will be used, following our [structured data guidelines](/search/docs/appearance/structured-data/sd-policies) does help our algorithms to have it available in a machine-readable way.\n- **Troubleshoot by minimizing other dates on the page**: If you've followed the best practices above and find incorrect dates are being selected, consider if you can remove or minimize other dates that may appear on the page, such as those that might be next to related stories.\n\n\nWe hope these guidelines help to make it easier to specify the right date on your website's\npages! For questions or comments on this, or other structured data topics, you can drop by our\n[webmaster help forums](https://support.google.com/webmasters/go/community).\n\n\nPosted by\n[John Mueller](https://johnmu.com/), Developer Advocate, Zurich"]]
