{"id":29145,"date":"2018-12-27T18:05:52","date_gmt":"2018-12-27T16:05:52","guid":{"rendered":"https:\/\/mamchenkov.net\/wordpress\/?p=29145"},"modified":"2018-12-27T18:07:09","modified_gmt":"2018-12-27T16:07:09","slug":"iso-8601-yyyy-yyyy-and-why-your-year-may-be-wrong","status":"publish","type":"post","link":"https:\/\/mamchenkov.net\/wordpress\/2018\/12\/27\/iso-8601-yyyy-yyyy-and-why-your-year-may-be-wrong\/","title":{"rendered":"ISO-8601, YYYY, yyyy, and why your year may be wrong"},"content":{"rendered":"<!-- google_ad_section_start -->\n\n<figure class=\"wp-block-image\"><img data-recalc-dims=\"1\" loading=\"lazy\" decoding=\"async\" width=\"660\" height=\"253\" data-attachment-id=\"29146\" data-permalink=\"https:\/\/mamchenkov.net\/wordpress\/2018\/12\/27\/iso-8601-yyyy-yyyy-and-why-your-year-may-be-wrong\/yyyy\/\" data-orig-file=\"https:\/\/i0.wp.com\/mamchenkov.net\/wordpress\/wp-content\/uploads\/2018\/12\/YYYY.png?fit=1024%2C393&amp;ssl=1\" data-orig-size=\"1024,393\" data-comments-opened=\"1\" data-image-meta=\"{&quot;aperture&quot;:&quot;0&quot;,&quot;credit&quot;:&quot;&quot;,&quot;camera&quot;:&quot;&quot;,&quot;caption&quot;:&quot;&quot;,&quot;created_timestamp&quot;:&quot;0&quot;,&quot;copyright&quot;:&quot;&quot;,&quot;focal_length&quot;:&quot;0&quot;,&quot;iso&quot;:&quot;0&quot;,&quot;shutter_speed&quot;:&quot;0&quot;,&quot;title&quot;:&quot;&quot;,&quot;orientation&quot;:&quot;0&quot;}\" data-image-title=\"YYYY\" data-image-description=\"\" data-image-caption=\"\" data-large-file=\"https:\/\/i0.wp.com\/mamchenkov.net\/wordpress\/wp-content\/uploads\/2018\/12\/YYYY.png?fit=660%2C253&amp;ssl=1\" src=\"https:\/\/i0.wp.com\/mamchenkov.net\/wordpress\/wp-content\/uploads\/2018\/12\/YYYY-1024x393.png?resize=660%2C253&#038;ssl=1\" alt=\"\" class=\"wp-image-29146\" srcset=\"https:\/\/i0.wp.com\/mamchenkov.net\/wordpress\/wp-content\/uploads\/2018\/12\/YYYY.png?w=1024&amp;ssl=1 1024w, https:\/\/i0.wp.com\/mamchenkov.net\/wordpress\/wp-content\/uploads\/2018\/12\/YYYY.png?resize=500%2C192&amp;ssl=1 500w, https:\/\/i0.wp.com\/mamchenkov.net\/wordpress\/wp-content\/uploads\/2018\/12\/YYYY.png?resize=768%2C295&amp;ssl=1 768w\" sizes=\"auto, (max-width: 660px) 100vw, 660px\" \/><\/figure>\n\n\n\n<p class=\"wp-block-paragraph\">Erica Sadun <a href=\"https:\/\/ericasadun.com\/2018\/12\/25\/iso-8601-yyyy-yyyy-and-why-your-year-may-be-wrong\/\">blog post<\/a> goes into details of the difference between &#8216;YYYY&#8217; and &#8216;yyyy&#8217; when formatting dates.  Remember to add a few unit tests to your application to make sure you are using the correct format.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">We&#8217;ve recently seen <a href=\"http:\/\/anvyst.com\/2018\/12\/date-formatting-week-of-year\/\">this issue at work<\/a> and it was a pain in the butt to troubleshoot.<\/p>\n<!-- google_ad_section_end -->\n","protected":false},"excerpt":{"rendered":"<!-- google_ad_section_start -->\n<p>Erica Sadun blog post goes into details of the difference between &#8216;YYYY&#8217; and &#8216;yyyy&#8217; when formatting dates. Remember to add a few unit tests to your application to make sure you are using the correct format. We&#8217;ve recently seen this issue at work and it was a pain in the butt to troubleshoot.<\/p>\n<!-- google_ad_section_end -->\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_monsterinsights_skip_tracking":false,"_monsterinsights_sitenote_active":false,"_monsterinsights_sitenote_note":"","_monsterinsights_sitenote_category":0,"_jetpack_newsletter_access":"","_jetpack_dont_email_post_to_subs":false,"_jetpack_newsletter_tier_id":0,"_jetpack_memberships_contains_paywalled_content":false,"_jetpack_feature_clip_id":0,"_jetpack_memberships_contains_paid_content":false,"footnotes":"","jetpack_publicize_message":"ISO-8601, YYYY, yyyy, and why your year may be wrong #WebDev #standards #bugs ","jetpack_publicize_feature_enabled":true,"jetpack_social_post_already_shared":true,"jetpack_social_options":{"image_generator_settings":{"template":"highway","default_image_id":0,"font":"","enabled":false},"version":2},"jetpack_post_was_ever_published":false,"_links_to":"","_links_to_target":""},"categories":[1,18,62,1334],"tags":[3069,1216,989,1330],"keyring_services":[],"class_list":["post-29145","post","type-post","status-publish","format-standard","hentry","category-general","category-programming","category-technology","category-web-work","tag-best-practices","tag-standards","tag-troubleshooting","tag-web-development"],"aioseo_notices":[],"aioseo_head":"\n\t\t<!-- All in One SEO 4.9.8 - aioseo.com -->\n\t<meta name=\"description\" content=\"Erica Sadun blog post goes into details of the difference between &#039;YYYY&#039; and &#039;yyyy&#039; when formatting dates. 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We've recently seen this issue at work and it was a pain in the butt to troubleshoot.","twitter:creator":"@mamchenkov","twitter:image":"https:\/\/mamchenkov.net\/wordpress\/wp-content\/uploads\/2026\/03\/leonid-sailing-beer.jpg"},"aioseo_meta_data":{"post_id":"29145","title":null,"description":null,"keywords":null,"keyphrases":null,"primary_term":null,"canonical_url":null,"og_title":null,"og_description":null,"og_object_type":"default","og_image_type":"default","og_image_url":null,"og_image_width":null,"og_image_height":null,"og_image_custom_url":null,"og_image_custom_fields":null,"og_video":null,"og_custom_url":null,"og_article_section":null,"og_article_tags":null,"twitter_use_og":false,"twitter_card":"default","twitter_image_type":"default","twitter_image_url":null,"twitter_image_custom_url":null,"twitter_image_custom_fields":null,"twitter_title":null,"twitter_description":null,"schema":{"blockGraphs":[],"customGraphs":[],"default":{"data":{"Article":[],"Course":[],"Dataset":[],"FAQPage":[],"Movie":[],"Person":[],"Product":[],"ProductReview":[],"Car":[],"Recipe":[],"Service":[],"SoftwareApplication":[],"WebPage":[]},"graphName":"BlogPosting","isEnabled":true},"graphs":[]},"schema_type":"default","schema_type_options":null,"pillar_content":false,"robots_default":true,"robots_noindex":false,"robots_noarchive":false,"robots_nosnippet":false,"robots_nofollow":false,"robots_noimageindex":false,"robots_noodp":false,"robots_notranslate":false,"robots_max_snippet":null,"robots_max_videopreview":null,"robots_max_imagepreview":"large","priority":null,"frequency":null,"local_seo":null,"breadcrumb_settings":null,"limit_modified_date":false,"ai":null,"created":"2023-07-19 08:57:12","updated":"2026-01-15 13:58:45","seo_analyzer_scan_date":null},"aioseo_breadcrumb":"<div class=\"aioseo-breadcrumbs\"><span class=\"aioseo-breadcrumb\">\n\t\t\t<a href=\"https:\/\/mamchenkov.net\/wordpress\" title=\"Home\">Home<\/a>\n\t\t<\/span><span class=\"aioseo-breadcrumb-separator\">&raquo;<\/span><span class=\"aioseo-breadcrumb\">\n\t\t\t<a href=\"https:\/\/mamchenkov.net\/wordpress\/category\/technology\/\" title=\"Technology\">Technology<\/a>\n\t\t<\/span><span class=\"aioseo-breadcrumb-separator\">&raquo;<\/span><span class=\"aioseo-breadcrumb\">\n\t\t\t<a href=\"https:\/\/mamchenkov.net\/wordpress\/category\/technology\/programming\/\" title=\"Programming\">Programming<\/a>\n\t\t<\/span><span class=\"aioseo-breadcrumb-separator\">&raquo;<\/span><span class=\"aioseo-breadcrumb\">\n\t\t\tISO-8601, YYYY, yyyy, and why your year may be wrong\n\t\t<\/span><\/div>","aioseo_breadcrumb_json":[{"label":"Home","link":"https:\/\/mamchenkov.net\/wordpress"},{"label":"Technology","link":"https:\/\/mamchenkov.net\/wordpress\/category\/technology\/"},{"label":"Programming","link":"https:\/\/mamchenkov.net\/wordpress\/category\/technology\/programming\/"},{"label":"ISO-8601, YYYY, yyyy, and why your year may be wrong","link":"https:\/\/mamchenkov.net\/wordpress\/2018\/12\/27\/iso-8601-yyyy-yyyy-and-why-your-year-may-be-wrong\/"}],"jetpack_publicize_connections":[],"jetpack_featured_media_url":"","jetpack-related-posts":[{"id":20210,"url":"https:\/\/mamchenkov.net\/wordpress\/2014\/02\/03\/list-of-minimalist-web-frameworks\/","url_meta":{"origin":29145,"position":0},"title":"List of minimalist web frameworks","author":"Leonid Mamchenkov","date":"February 3, 2014","format":"link","excerpt":"List of minimalist web frameworks Framework for CSS Web Framework for C Frameworks for Front-end JS Web framework for Go Web framework for Haskell Web framework for Java Web framework for Javascript Web framework for Lua Web framework for Node.js Web framework for Perl Web framework for PHP Web framework\u2026","rel":"","context":"In &quot;All&quot;","block_context":{"text":"All","link":"https:\/\/mamchenkov.net\/wordpress\/category\/general\/"},"img":{"alt_text":"","src":"","width":0,"height":0},"classes":[]},{"id":21699,"url":"https:\/\/mamchenkov.net\/wordpress\/2014\/04\/25\/voice-elements-web-components-for-web-speech-api\/","url_meta":{"origin":29145,"position":1},"title":"Voice Elements &#8211; 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