{"id":4168,"date":"2017-05-06T23:25:02","date_gmt":"2017-05-06T21:25:02","guid":{"rendered":"https:\/\/www.sheetgo.com\/?p=4168"},"modified":"2017-05-06T23:25:02","modified_gmt":"2017-05-06T21:25:02","slug":"formule-du-semainier-google-sheets","status":"publish","type":"post","link":"https:\/\/www.sheetgo.com\/fr\/blog\/google-sheets-formulas\/weeknum-formula-google-sheets\/","title":{"rendered":"Comment utiliser la formule WEEKNUM dans Google Sheets ?"},"content":{"rendered":"<p>[et_pb_section fb_built=&#8221;1&#8243; admin_label=&#8221;section&#8221; module_class=&#8221;sheetgo-post&#8221; _builder_version=&#8221;4.16&#8243; global_colors_info=&#8221;{}&#8221; theme_builder_area=&#8221;post_content&#8221;][et_pb_row admin_label=&#8221;row&#8221; _builder_version=&#8221;4.16&#8243; background_size=&#8221;initial&#8221; background_position=&#8221;top_left&#8221; background_repeat=&#8221;repeat&#8221; global_colors_info=&#8221;{}&#8221; theme_builder_area=&#8221;post_content&#8221;][et_pb_column type=&#8221;4_4&#8243; _builder_version=&#8221;4.16&#8243; custom_padding=&#8221;|||&#8221; global_colors_info=&#8221;{}&#8221; custom_padding__hover=&#8221;|||&#8221; theme_builder_area=&#8221;post_content&#8221;][et_pb_text _builder_version=&#8221;4.16&#8243; global_colors_info=&#8221;{}&#8221; theme_builder_area=&#8221;post_content&#8221;]<\/p>\n<p>In Google Sheets, if you need to know what specific week of the year a date falls on, you can use the<span>\u00a0<\/span><a href=\"https:\/\/support.google.com\/docs\/answer\/3294949?hl=en\" target=\"_blank\" rel=\"noopener noreferrer\">WEEKNUM<\/a><span>\u00a0<\/span>formula to find out. The week numbers will range from 1 to 53.<\/p>\n<h3>Syntax<\/h3>\n<p><span><strong>WEEKNUM(date, [type])<\/strong><\/span><\/p>\n<ul>\n<li><span><strong>date<\/strong><\/span><span>\u00a0<\/span>\u2013 is the input date that the formula uses to determine the week of the year. This can be a reference to a cell that holds a date, or a formula that returns a date. Not only that, it can even be a number that the Google Sheets can evaluate to a date value.<\/li>\n<li><span><strong>type<\/strong><\/span><span>\u00a0<\/span>\u2013 this is an optional indicator that lets the formula know which day to begin the week. As Google&#8217;s<span>\u00a0<\/span><a href=\"https:\/\/support.google.com\/docs\/answer\/3294949?hl=en\" target=\"_blank\" rel=\"noopener noreferrer\">documentation<\/a>\u00a0explains, the valid inputs for this parameter are 1, 2, 11 through to 17 and 21. There are also two different week numbering systems the formula uses to return the output.\n<ul>\n<li>System 1: The week containing <strong>January 1<\/strong>, is week 1. All types <strong>except 21<\/strong> use this system.<\/li>\n<li>System 2: The week that containing <strong>the first Thursday of the year<\/strong> is week 1. <strong>Type 21<\/strong> uses this system, which often goes by the name \u201cEuropean system for numbering weeks\u201d.<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n<p>Now that we have seen what each system signifies, let&#8217;s take a look at what each WEEKNUM formula type stands for. Look at the table below. It shows the week\u2019s start day and end day for each type.<\/p>\n<p>[\/et_pb_text][et_pb_text admin_label=&#8221;Connections T &#8211; Automate between spreadsheets &#8211; Horizontal&#8221; module_class=&#8221;sheetgo-post-no-shadow-img md2-contained-button-light vertical-banner-container&#8221; _builder_version=&#8221;4.27.2&#8243; _module_preset=&#8221;default&#8221; background_color=&#8221;#f2f7ff&#8221; max_width=&#8221;700px&#8221; module_alignment=&#8221;center&#8221; max_height=&#8221;300px&#8221; custom_margin=&#8221;20px|0px|20px|0px|true|true&#8221; custom_padding=&#8221;25px|25px|25px|25px|true|true&#8221; sticky_limit_bottom=&#8221;section&#8221; border_radii=&#8221;on|20px|20px|20px|20px&#8221; border_width_all=&#8221;1px&#8221; border_color_all=&#8221;#d9e7ff&#8221; saved_tabs=&#8221;all&#8221; global_colors_info=&#8221;{}&#8221; global_module=&#8221;50460&#8243; theme_builder_area=&#8221;post_content&#8221;]<img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/static.sheetgo.com\/wp-content\/uploads\/2024\/09\/run-automatically-connect-sheet-icons.webp\" width=\"250\" height=\"168\" alt=\"\" \/><\/p>\n<p><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/static.sheetgo.com\/wp-content\/uploads\/2024\/09\/Recommended-for-Google-Workspace-badge.webp\" width=\"150\" height=\"180\" alt=\"39\" \/><\/p>\n<p><span style=\"font-size: 22px; font-weight: 600;\">Automate data transfers between spreadsheets<br \/>\n<\/span><\/p>\n<p><a href=\"https:\/\/www.sheetgo.com\/connections\/\" target=\"_blank\" rel=\"noopener\">Find out how<\/a>[\/et_pb_text][et_pb_image src=&#8221;https:\/\/static.sheetgo.com\/wp-content\/uploads\/2021\/10\/WEEKNUM-formula-1.png&#8221; alt=&#8221;WEEKNUM formula 1&#8243; title_text=&#8221;WEEKNUM formula 1&#8243; _builder_version=&#8221;4.16&#8243; _module_preset=&#8221;default&#8221; global_colors_info=&#8221;{}&#8221; theme_builder_area=&#8221;post_content&#8221;][\/et_pb_image][et_pb_text _builder_version=&#8221;4.16&#8243; global_colors_info=&#8221;{}&#8221; theme_builder_area=&#8221;post_content&#8221;]<\/p>\n<h3>How to use the WEEKNUM Formula<\/h3>\n<p>To see the formula in action, take a look at the screenshot below. We have listed a series of dates in column A. The subsequent columns contain the WEEKNUM formulas applied for each available type.<\/p>\n<p>[\/et_pb_text][et_pb_image src=&#8221;https:\/\/static.sheetgo.com\/wp-content\/uploads\/2017\/10\/frame-generic-1.png&#8221; alt=&#8221;WEEKNUM Formula: Usage&#8221; title_text=&#8221;weeknum-formula-usage&#8221; align=&#8221;center&#8221; module_class=&#8221;sheetgo-post-no-shadow-img&#8221; _builder_version=&#8221;4.16&#8243; width=&#8221;640px&#8221; max_width=&#8221;640px&#8221; height=&#8221;440px&#8221; max_height=&#8221;440px&#8221; global_colors_info=&#8221;{}&#8221; theme_builder_area=&#8221;post_content&#8221;][\/et_pb_image][et_pb_text admin_label=&#8221;Connections T &#8211; Automate beyond importrange &#8211; Horizontal&#8221; module_class=&#8221;sheetgo-post-no-shadow-img md2-contained-button-light vertical-banner-container&#8221; _builder_version=&#8221;4.27.2&#8243; _module_preset=&#8221;default&#8221; background_color=&#8221;#f2f7ff&#8221; max_width=&#8221;700px&#8221; module_alignment=&#8221;center&#8221; max_height=&#8221;300px&#8221; custom_margin=&#8221;20px|0px|20px|0px|true|true&#8221; custom_padding=&#8221;25px|25px|25px|25px|true|true&#8221; sticky_limit_bottom=&#8221;section&#8221; border_radii=&#8221;on|20px|20px|20px|20px&#8221; border_width_all=&#8221;1px&#8221; border_color_all=&#8221;#d9e7ff&#8221; saved_tabs=&#8221;all&#8221; global_colors_info=&#8221;{}&#8221; global_module=&#8221;50462&#8243; theme_builder_area=&#8221;post_content&#8221;]<img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/static.sheetgo.com\/wp-content\/uploads\/2024\/09\/Add-on-sm_sheets-connected-new-connection.webp\" width=\"250\" height=\"168\" alt=\"\" \/><\/p>\n<p><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/static.sheetgo.com\/wp-content\/uploads\/2024\/09\/Recommended-for-Google-Workspace-badge.webp\" width=\"150\" height=\"180\" alt=\"39\" \/><\/p>\n<p><span style=\"font-size: 22px; font-weight: 600;\">Automate data transfers beyond Importrange<\/span><\/p>\n<p><a href=\"https:\/\/www.sheetgo.com\/connections\/\" target=\"_blank\" rel=\"noopener\">Find out how<\/a>[\/et_pb_text][et_pb_text _builder_version=&#8221;4.16&#8243; global_colors_info=&#8221;{}&#8221; theme_builder_area=&#8221;post_content&#8221;]<\/p>\n<p>Let&#8217;s pick type 11 and understand how the formula works. Since this type uses System 1 to calculate week numbers, it considers the week with January 1 as week 1. And, according to the previous table, the week starts on Monday and ends on Sunday for this type. Therefore, week 1 spans from January 1, Friday to January 3, Sunday. Week 2 starts from January 4, as it is Monday, and ends on January 10, Sunday.<\/p>\n<p>Now, let&#8217;s look at type 21. This uses <strong>System 2<\/strong>, which assumes that the week with <strong>the first Thursday of the year<\/strong>\u00a0is week 1. Taking a quick glance at the data, we know that the first Thursday of the year falls on January 8. And, looking at the table in the first screenshot, the week starts on Monday and ends on Sunday for this type as well. So, week 1 starts on Monday January 4 and ends on Sunday January 10. What about the initial three days that are not part of week 1? The WEEKNUM formula assigns them the last week number of the previous year, which is 53 in this case.<\/p>\n<p>Do you need to check what day of the week it was on a given date? In this case, use the WEEKDAY formula in Google Sheets. Read<span>\u00a0<\/span><a href=\"https:\/\/www.sheetgo.com\/blog\/google-sheets-formulas\/weekday-formula-google-sheets\/\" target=\"_blank\" rel=\"noopener noreferrer\">this blog post<\/a><span>\u00a0<\/span>to learn how to use it.<\/p>\n<p>[\/et_pb_text][\/et_pb_column][\/et_pb_row][\/et_pb_section]<\/p>\n","protected":false},"excerpt":{"rendered":"<p>In Google Sheets, if you need to know what specific week of the year a date falls on, you can use the\u00a0WEEKNUM\u00a0formula to find out. The week numbers will range from 1 to 53. Syntax WEEKNUM(date, [type]) date\u00a0\u2013 is the input date that the formula uses to determine the week of the year. This can [&hellip;]<\/p>\n","protected":false},"author":40,"featured_media":4386,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"_et_pb_use_builder":"on","_et_pb_old_content":"In Google Sheets, if we need to know what specific week a date falls on, we can make use of the <a href=\"https:\/\/support.google.com\/docs\/answer\/3294949?hl=en\" target=\"_blank\" rel=\"noopener noreferrer\">WEEKNUM<\/a> formula to find that out. The week numbers will range from 1 to 53.\n<h3>Syntax<\/h3>\n<span style=\"font-family: courier new,courier,monospace; font-size: 14pt;\"><strong>WEEKNUM(date, [type])<\/strong><\/span>\n<ul>\n \t<li><span style=\"font-family: courier new,courier,monospace; font-size: 12pt;\"><strong>date<\/strong><\/span> - is the input date that the formula uses to determine the week of the year. This can be a reference to a cell that holds a date, or a formula that returns a date. Not only that, it can even be a number that the Google Sheets can evaluate to a date value.<\/li>\n \t<li><span style=\"font-family: courier new,courier,monospace; font-size: 12pt;\"><strong>type<\/strong><\/span> - this is an optional indicator that lets the formula know where to begin the week from. As per the official <a href=\"https:\/\/support.google.com\/docs\/answer\/3294949?hl=en\" target=\"_blank\" rel=\"noopener noreferrer\">documentation<\/a>, the valid inputs for this parameter are 1, 2, 11 through to 17 and 21. Also, there are two different week numbering systems the formula uses to return the output.\n<ul>\n \t<li>System 1: The week that has January 1, is week # 1. All the types except 21 use this system.<\/li>\n \t<li>System 2: The week that consists of the year's first Thursday are week # 1.Type 21 uses this system, which often goes by the name \"European system for numbering weeks\".<\/li>\n<\/ul>\n<\/li>\n<\/ul>\nNow that we have seen what each system signifies, let us also understand what each WEEKNUM formula type stands for. Please consider the table below. It shows what each type represents in terms of the week's starting day and the week's ending day.\n\n<img class=\"aligncenter size-full wp-image-4170\" src=\"https:\/\/static.sheetgo.com\/wp-content\/uploads\/2017\/10\/frame-generic.png\" alt=\"WEEKNUM Formula - Illustration 2\" width=\"418\" height=\"268\">\n<h3>Usage: WEEKNUM Formula<\/h3>\nLet us dive into the practical application of the formula so that we get a clearer picture of its working. Please see the snapshot below. We have listed a series of dates column A. And, the subsequent columns contain the WEEKNUM formulas applied for each available type of those dates.\n\n<img class=\"aligncenter size-full wp-image-4169\" src=\"https:\/\/static.sheetgo.com\/wp-content\/uploads\/2017\/10\/frame-generic-1.png\" alt=\"WEEKNUM Formula - Illustration 1\" width=\"923\" height=\"579\">\n\nLet us pick the type 11 and understand how the formula works. Since this type uses System 1 to calculate week numbers, it considers the week with January 1 as week # 1. And, according to the previous table, the week starts on Monday and ends on Sunday for this type. Therefore, week # 1 spans from January 1, Friday to January 3, Sunday. Week # 2 starts from January 4, as it is Monday, and ends on January 10, Sunday.\n\nNow, we will try and understand the case of type 21. This uses System 2, that assumes a week with year's first Thursday as week # 1. Taking a quick glance at the data, we know that the first Thursday of the year falls on January 8. And, going by the first snapshot, the week starts on Monday and ends on Sunday for this type as well. So, the week # 1 starts from January 4, Monday and ends on January 10, Sunday. What about the initial 3 days that are not part of week # 1? The WEEKNUM formula assigns it the previous year's last week number, which is 53 in this case.\n\n&nbsp;","_et_gb_content_width":"","footnotes":""},"categories":[54],"tags":[39,28],"class_list":["post-4168","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-google-sheets-formulas","tag-connections-t","tag-spreadsheets"],"acf":[],"_links":{"self":[{"href":"https:\/\/www.sheetgo.com\/fr\/wp-json\/wp\/v2\/posts\/4168","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.sheetgo.com\/fr\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.sheetgo.com\/fr\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.sheetgo.com\/fr\/wp-json\/wp\/v2\/users\/40"}],"replies":[{"embeddable":true,"href":"https:\/\/www.sheetgo.com\/fr\/wp-json\/wp\/v2\/comments?post=4168"}],"version-history":[{"count":0,"href":"https:\/\/www.sheetgo.com\/fr\/wp-json\/wp\/v2\/posts\/4168\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.sheetgo.com\/fr\/wp-json\/wp\/v2\/media\/4386"}],"wp:attachment":[{"href":"https:\/\/www.sheetgo.com\/fr\/wp-json\/wp\/v2\/media?parent=4168"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.sheetgo.com\/fr\/wp-json\/wp\/v2\/categories?post=4168"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.sheetgo.com\/fr\/wp-json\/wp\/v2\/tags?post=4168"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}