diff --git a/00-intro.html b/00-intro.html
index 0a064d71..1b21f1da 100644
--- a/00-intro.html
+++ b/00-intro.html
@@ -265,7 +265,7 @@ <h2 class="accordion-header" id="flush-headingTwelve">
       </div>
       <hr></nav><main id="main-content" class="main-content"><div class="container lesson-content">
         <h1>Introduction</h1>
-        <p>Last updated on 2023-05-03 |
+        <p>Last updated on 2024-06-13 |
         
         <a href="https://github.com/datacarpentry/spreadsheet-ecology-lesson/edit/main/episodes/00-intro.md" class="external-link">Edit this page <i aria-hidden="true" data-feather="edit"></i></a></p>
         
@@ -328,8 +328,8 @@ <h3 id="what-this-lesson-will-not-teach-you">What this lesson will not teach you
 <ul><li>How to do <em>statistics</em> in a spreadsheet</li>
 <li>How to do <em>plotting</em> in a spreadsheet</li>
 <li>How to <em>write code</em> in spreadsheet programs</li>
-</ul><p>If you’re looking to do this, a good reference is <a href="https://www.amazon.com/Head-First-Excel-learners-spreadsheets/dp/0596807694/" class="external-link">Head
-First Excel</a>, published by O’Reilly.</p>
+</ul><p>If you’re looking to do this, a good reference is <a href="https://www.amazon.com/Excel-Cookbook-Recipes-Mastering-Microsoft/dp/1098143329/" class="external-link">Excel
+Cookbook</a>, published by O’Reilly.</p>
 <hr></div>
 <div class="section level3">
 <h3 id="why-arent-we-teaching-data-analysis-in-spreadsheets">Why aren’t we teaching data analysis in spreadsheets<a class="anchor" aria-label="anchor" href="#why-arent-we-teaching-data-analysis-in-spreadsheets"></a></h3>
@@ -492,7 +492,7 @@ <h3 class="callout-title">Key Points<a class="anchor" aria-label="anchor" href="
   "url": "https://datacarpentry.github.io/spreadsheet-ecology-lesson/00-intro.html",
   "identifier": "https://datacarpentry.github.io/spreadsheet-ecology-lesson/00-intro.html",
   "dateCreated": "2015-03-09",
-  "dateModified": "2023-05-03",
+  "dateModified": "2024-06-13",
   "datePublished": "2024-06-13"
 }
 
diff --git a/01-format-data.html b/01-format-data.html
index 5960456c..914bc5b8 100644
--- a/01-format-data.html
+++ b/01-format-data.html
@@ -448,7 +448,7 @@ <h3 class="callout-title">Exercise<a class="anchor" aria-label="anchor" href="#e
 <button class="accordion-button solution-button collapsed" type="button" data-bs-toggle="collapse" data-bs-target="#collapseSolution1" aria-expanded="false" aria-controls="collapseSolution1">
   <h4 class="accordion-header" id="headingSolution1">Show me the solution</h4>
 </button>
-<div id="collapseSolution1" class="accordion-collapse collapse" data-bs-parent="#accordionSolution1" aria-labelledby="headingSolution1">
+<div id="collapseSolution1" class="accordion-collapse collapse" aria-labelledby="headingSolution1" data-bs-parent="#accordionSolution1">
 <div class="accordion-body">
 <ul><li>Take about 10 minutes to work on this exercise.</li>
 <li>All the mistakes in <a href="02-common-mistakes.html">02-common-mistakes</a> are present in the
diff --git a/03-dates-as-data.html b/03-dates-as-data.html
index baf036b6..ddce6adc 100644
--- a/03-dates-as-data.html
+++ b/03-dates-as-data.html
@@ -361,7 +361,7 @@ <h3 class="callout-title">Exercise<a class="anchor" aria-label="anchor" href="#e
 <button class="accordion-button solution-button collapsed" type="button" data-bs-toggle="collapse" data-bs-target="#collapseSolution1" aria-expanded="false" aria-controls="collapseSolution1">
   <h4 class="accordion-header" id="headingSolution1">Show me the solution</h4>
 </button>
-<div id="collapseSolution1" class="accordion-collapse collapse" aria-labelledby="headingSolution1" data-bs-parent="#accordionSolution1">
+<div id="collapseSolution1" class="accordion-collapse collapse" data-bs-parent="#accordionSolution1" aria-labelledby="headingSolution1">
 <div class="accordion-body">
 <p><img src="fig/solution_exercise_1_dates.png" class="figure"> {alt=‘dates, exersize
 1’ .output}</p>
@@ -399,7 +399,7 @@ <h3 class="callout-title">Exercise<a class="anchor" aria-label="anchor" href="#e
 <button class="accordion-button solution-button collapsed" type="button" data-bs-toggle="collapse" data-bs-target="#collapseSolution2" aria-expanded="false" aria-controls="collapseSolution2">
   <h4 class="accordion-header" id="headingSolution2">Show me the solution</h4>
 </button>
-<div id="collapseSolution2" class="accordion-collapse collapse" aria-labelledby="headingSolution2" data-bs-parent="#accordionSolution2">
+<div id="collapseSolution2" class="accordion-collapse collapse" data-bs-parent="#accordionSolution2" aria-labelledby="headingSolution2">
 <div class="accordion-body">
 <ol style="list-style-type: decimal"><li>To get the year, type <code>=YEAR(NOW())</code> into any cell in
 your spreadsheet. To get the month, type <code>=MONTH(NOW())</code>. To
@@ -499,7 +499,7 @@ <h3 class="callout-title">Exercise<a class="anchor" aria-label="anchor" href="#e
 <button class="accordion-button solution-button collapsed" type="button" data-bs-toggle="collapse" data-bs-target="#collapseSolution3" aria-expanded="false" aria-controls="collapseSolution3">
   <h4 class="accordion-header" id="headingSolution3">Show me the solution</h4>
 </button>
-<div id="collapseSolution3" class="accordion-collapse collapse" aria-labelledby="headingSolution3" data-bs-parent="#accordionSolution3">
+<div id="collapseSolution3" class="accordion-collapse collapse" data-bs-parent="#accordionSolution3" aria-labelledby="headingSolution3">
 <div class="accordion-body">
 <ul><li>Click to the <code>dates</code> tab of the workbook and double-click
 on any of the values in the <code>Date collected</code> column. Notice
diff --git a/04-quality-control.html b/04-quality-control.html
index f3e815a9..756d1b4f 100644
--- a/04-quality-control.html
+++ b/04-quality-control.html
@@ -406,7 +406,7 @@ <h3 class="callout-title">Exercise<a class="anchor" aria-label="anchor" href="#e
 <button class="accordion-button solution-button collapsed" type="button" data-bs-toggle="collapse" data-bs-target="#collapseSolution1" aria-expanded="false" aria-controls="collapseSolution1">
   <h4 class="accordion-header" id="headingSolution1">Show me the solution</h4>
 </button>
-<div id="collapseSolution1" class="accordion-collapse collapse" data-bs-parent="#accordionSolution1" aria-labelledby="headingSolution1">
+<div id="collapseSolution1" class="accordion-collapse collapse" aria-labelledby="headingSolution1" data-bs-parent="#accordionSolution1">
 <div class="accordion-body">
 <p>Click the Sort button on the data tab in Excel. A pop-up will appear.
 Make sure you select <code>Expand the selection</code>.</p>
@@ -459,7 +459,7 @@ <h3 class="callout-title">Exercise<a class="anchor" aria-label="anchor" href="#e
 <button class="accordion-button solution-button collapsed" type="button" data-bs-toggle="collapse" data-bs-target="#collapseSolution2" aria-expanded="false" aria-controls="collapseSolution2">
   <h4 class="accordion-header" id="headingSolution2">Show me the solution</h4>
 </button>
-<div id="collapseSolution2" class="accordion-collapse collapse" data-bs-parent="#accordionSolution2" aria-labelledby="headingSolution2">
+<div id="collapseSolution2" class="accordion-collapse collapse" aria-labelledby="headingSolution2" data-bs-parent="#accordionSolution2">
 <div class="accordion-body">
 <p>Cells that contain non-numerical values are not colored. This
 includes both the cells where the letter “g” was included and the empty
diff --git a/aio.html b/aio.html
index 2713e35a..fe6c2e19 100644
--- a/aio.html
+++ b/aio.html
@@ -305,7 +305,7 @@ <h2 class="accordion-header" id="flush-headingTwelve">
         
 <section id="aio-00-intro"><p>Content from <a href="00-intro.html">Introduction</a></p>
 <hr>
-<p>Last updated on 2023-05-03 |
+<p>Last updated on 2024-06-13 |
         
         <a href="https://github.com/datacarpentry/spreadsheet-ecology-lesson/edit/main/episodes/00-intro.md" class="external-link">Edit this page <i aria-hidden="true" data-feather="edit"></i></a></p>
 <div class="text-end">
@@ -372,8 +372,8 @@ <h3 id="what-this-lesson-will-not-teach-you">What this lesson will not teach you
 <li>How to do <em>plotting</em> in a spreadsheet</li>
 <li>How to <em>write code</em> in spreadsheet programs</li>
 </ul>
-<p>If you’re looking to do this, a good reference is <a href="https://www.amazon.com/Head-First-Excel-learners-spreadsheets/dp/0596807694/" class="external-link">Head
-First Excel</a>, published by O’Reilly.</p>
+<p>If you’re looking to do this, a good reference is <a href="https://www.amazon.com/Excel-Cookbook-Recipes-Mastering-Microsoft/dp/1098143329/" class="external-link">Excel
+Cookbook</a>, published by O’Reilly.</p>
 <hr>
 </div>
 <div class="section level3">
@@ -692,7 +692,7 @@ <h3 class="callout-title">Exercise<a class="anchor" aria-label="anchor" href="#e
 <button class="accordion-button solution-button collapsed" type="button" data-bs-toggle="collapse" data-bs-target="#collapseSolution1" aria-expanded="false" aria-controls="collapseSolution1">
   <h4 class="accordion-header" id="headingSolution1">Show me the solution</h4>
 </button>
-<div id="collapseSolution1" class="accordion-collapse collapse" data-bs-parent="#accordionSolution1" aria-labelledby="headingSolution1">
+<div id="collapseSolution1" class="accordion-collapse collapse" aria-labelledby="headingSolution1" data-bs-parent="#accordionSolution1">
 <div class="accordion-body">
 <ul>
 <li>Take about 10 minutes to work on this exercise.</li>
@@ -1399,7 +1399,7 @@ <h3 class="callout-title">Exercise<a class="anchor" aria-label="anchor" href="#e
 <button class="accordion-button solution-button collapsed" type="button" data-bs-toggle="collapse" data-bs-target="#collapseSolution1" aria-expanded="false" aria-controls="collapseSolution1">
   <h4 class="accordion-header" id="headingSolution1">Show me the solution</h4>
 </button>
-<div id="collapseSolution1" class="accordion-collapse collapse" aria-labelledby="headingSolution1" data-bs-parent="#accordionSolution1">
+<div id="collapseSolution1" class="accordion-collapse collapse" data-bs-parent="#accordionSolution1" aria-labelledby="headingSolution1">
 <div class="accordion-body">
 <p><img src="fig/solution_exercise_1_dates.png" class="figure"> {alt=‘dates, exersize
 1’ .output}</p>
@@ -1439,7 +1439,7 @@ <h3 class="callout-title">Exercise<a class="anchor" aria-label="anchor" href="#e
 <button class="accordion-button solution-button collapsed" type="button" data-bs-toggle="collapse" data-bs-target="#collapseSolution2" aria-expanded="false" aria-controls="collapseSolution2">
   <h4 class="accordion-header" id="headingSolution2">Show me the solution</h4>
 </button>
-<div id="collapseSolution2" class="accordion-collapse collapse" aria-labelledby="headingSolution2" data-bs-parent="#accordionSolution2">
+<div id="collapseSolution2" class="accordion-collapse collapse" data-bs-parent="#accordionSolution2" aria-labelledby="headingSolution2">
 <div class="accordion-body">
 <ol style="list-style-type: decimal">
 <li>To get the year, type <code>=YEAR(NOW())</code> into any cell in
@@ -1546,7 +1546,7 @@ <h3 class="callout-title">Exercise<a class="anchor" aria-label="anchor" href="#e
 <button class="accordion-button solution-button collapsed" type="button" data-bs-toggle="collapse" data-bs-target="#collapseSolution3" aria-expanded="false" aria-controls="collapseSolution3">
   <h4 class="accordion-header" id="headingSolution3">Show me the solution</h4>
 </button>
-<div id="collapseSolution3" class="accordion-collapse collapse" aria-labelledby="headingSolution3" data-bs-parent="#accordionSolution3">
+<div id="collapseSolution3" class="accordion-collapse collapse" data-bs-parent="#accordionSolution3" aria-labelledby="headingSolution3">
 <div class="accordion-body">
 <ul>
 <li>Click to the <code>dates</code> tab of the workbook and double-click
@@ -1796,7 +1796,7 @@ <h3 class="callout-title">Exercise<a class="anchor" aria-label="anchor" href="#e
 <button class="accordion-button solution-button collapsed" type="button" data-bs-toggle="collapse" data-bs-target="#collapseSolution1" aria-expanded="false" aria-controls="collapseSolution1">
   <h4 class="accordion-header" id="headingSolution1">Show me the solution</h4>
 </button>
-<div id="collapseSolution1" class="accordion-collapse collapse" data-bs-parent="#accordionSolution1" aria-labelledby="headingSolution1">
+<div id="collapseSolution1" class="accordion-collapse collapse" aria-labelledby="headingSolution1" data-bs-parent="#accordionSolution1">
 <div class="accordion-body">
 <p>Click the Sort button on the data tab in Excel. A pop-up will appear.
 Make sure you select <code>Expand the selection</code>.</p>
@@ -1852,7 +1852,7 @@ <h3 class="callout-title">Exercise<a class="anchor" aria-label="anchor" href="#e
 <button class="accordion-button solution-button collapsed" type="button" data-bs-toggle="collapse" data-bs-target="#collapseSolution2" aria-expanded="false" aria-controls="collapseSolution2">
   <h4 class="accordion-header" id="headingSolution2">Show me the solution</h4>
 </button>
-<div id="collapseSolution2" class="accordion-collapse collapse" data-bs-parent="#accordionSolution2" aria-labelledby="headingSolution2">
+<div id="collapseSolution2" class="accordion-collapse collapse" aria-labelledby="headingSolution2" data-bs-parent="#accordionSolution2">
 <div class="accordion-body">
 <p>Cells that contain non-numerical values are not colored. This
 includes both the cells where the letter “g” was included and the empty
diff --git a/instructor/00-intro.html b/instructor/00-intro.html
index c20269a0..459e6db2 100644
--- a/instructor/00-intro.html
+++ b/instructor/00-intro.html
@@ -265,7 +265,7 @@ <h2 class="accordion-header" id="flush-headingTwelve">
       </div>
       <hr></nav><main id="main-content" class="main-content"><div class="container lesson-content">
         <h1>Introduction</h1>
-        <p>Last updated on 2023-05-03 |
+        <p>Last updated on 2024-06-13 |
         
         <a href="https://github.com/datacarpentry/spreadsheet-ecology-lesson/edit/main/episodes/00-intro.md" class="external-link">Edit this page <i aria-hidden="true" data-feather="edit"></i></a></p>
         
@@ -330,8 +330,8 @@ <h3 id="what-this-lesson-will-not-teach-you">What this lesson will not teach you
 <ul><li>How to do <em>statistics</em> in a spreadsheet</li>
 <li>How to do <em>plotting</em> in a spreadsheet</li>
 <li>How to <em>write code</em> in spreadsheet programs</li>
-</ul><p>If you’re looking to do this, a good reference is <a href="https://www.amazon.com/Head-First-Excel-learners-spreadsheets/dp/0596807694/" class="external-link">Head
-First Excel</a>, published by O’Reilly.</p>
+</ul><p>If you’re looking to do this, a good reference is <a href="https://www.amazon.com/Excel-Cookbook-Recipes-Mastering-Microsoft/dp/1098143329/" class="external-link">Excel
+Cookbook</a>, published by O’Reilly.</p>
 <hr></div>
 <div class="section level3">
 <h3 id="why-arent-we-teaching-data-analysis-in-spreadsheets">Why aren’t we teaching data analysis in spreadsheets<a class="anchor" aria-label="anchor" href="#why-arent-we-teaching-data-analysis-in-spreadsheets"></a></h3>
@@ -494,7 +494,7 @@ <h3 class="callout-title">Key Points<a class="anchor" aria-label="anchor" href="
   "url": "https://datacarpentry.github.io/spreadsheet-ecology-lesson/instructor/00-intro.html",
   "identifier": "https://datacarpentry.github.io/spreadsheet-ecology-lesson/instructor/00-intro.html",
   "dateCreated": "2015-03-09",
-  "dateModified": "2023-05-03",
+  "dateModified": "2024-06-13",
   "datePublished": "2024-06-13"
 }
 
diff --git a/instructor/01-format-data.html b/instructor/01-format-data.html
index cdd87ab5..a02e6e6a 100644
--- a/instructor/01-format-data.html
+++ b/instructor/01-format-data.html
@@ -450,7 +450,7 @@ <h3 class="callout-title">Exercise<a class="anchor" aria-label="anchor" href="#e
 <button class="accordion-button solution-button collapsed" type="button" data-bs-toggle="collapse" data-bs-target="#collapseSolution1" aria-expanded="false" aria-controls="collapseSolution1">
   <h4 class="accordion-header" id="headingSolution1">Show me the solution</h4>
 </button>
-<div id="collapseSolution1" class="accordion-collapse collapse" data-bs-parent="#accordionSolution1" aria-labelledby="headingSolution1">
+<div id="collapseSolution1" class="accordion-collapse collapse" aria-labelledby="headingSolution1" data-bs-parent="#accordionSolution1">
 <div class="accordion-body">
 <ul><li>Take about 10 minutes to work on this exercise.</li>
 <li>All the mistakes in <a href="02-common-mistakes.html">02-common-mistakes</a> are present in the
diff --git a/instructor/03-dates-as-data.html b/instructor/03-dates-as-data.html
index d7aa18cf..04538ae2 100644
--- a/instructor/03-dates-as-data.html
+++ b/instructor/03-dates-as-data.html
@@ -363,7 +363,7 @@ <h3 class="callout-title">Exercise<a class="anchor" aria-label="anchor" href="#e
 <button class="accordion-button solution-button collapsed" type="button" data-bs-toggle="collapse" data-bs-target="#collapseSolution1" aria-expanded="false" aria-controls="collapseSolution1">
   <h4 class="accordion-header" id="headingSolution1">Show me the solution</h4>
 </button>
-<div id="collapseSolution1" class="accordion-collapse collapse" aria-labelledby="headingSolution1" data-bs-parent="#accordionSolution1">
+<div id="collapseSolution1" class="accordion-collapse collapse" data-bs-parent="#accordionSolution1" aria-labelledby="headingSolution1">
 <div class="accordion-body">
 <p><img src="../fig/solution_exercise_1_dates.png" class="figure"> {alt=‘dates, exersize
 1’ .output}</p>
@@ -401,7 +401,7 @@ <h3 class="callout-title">Exercise<a class="anchor" aria-label="anchor" href="#e
 <button class="accordion-button solution-button collapsed" type="button" data-bs-toggle="collapse" data-bs-target="#collapseSolution2" aria-expanded="false" aria-controls="collapseSolution2">
   <h4 class="accordion-header" id="headingSolution2">Show me the solution</h4>
 </button>
-<div id="collapseSolution2" class="accordion-collapse collapse" aria-labelledby="headingSolution2" data-bs-parent="#accordionSolution2">
+<div id="collapseSolution2" class="accordion-collapse collapse" data-bs-parent="#accordionSolution2" aria-labelledby="headingSolution2">
 <div class="accordion-body">
 <ol style="list-style-type: decimal"><li>To get the year, type <code>=YEAR(NOW())</code> into any cell in
 your spreadsheet. To get the month, type <code>=MONTH(NOW())</code>. To
@@ -501,7 +501,7 @@ <h3 class="callout-title">Exercise<a class="anchor" aria-label="anchor" href="#e
 <button class="accordion-button solution-button collapsed" type="button" data-bs-toggle="collapse" data-bs-target="#collapseSolution3" aria-expanded="false" aria-controls="collapseSolution3">
   <h4 class="accordion-header" id="headingSolution3">Show me the solution</h4>
 </button>
-<div id="collapseSolution3" class="accordion-collapse collapse" aria-labelledby="headingSolution3" data-bs-parent="#accordionSolution3">
+<div id="collapseSolution3" class="accordion-collapse collapse" data-bs-parent="#accordionSolution3" aria-labelledby="headingSolution3">
 <div class="accordion-body">
 <ul><li>Click to the <code>dates</code> tab of the workbook and double-click
 on any of the values in the <code>Date collected</code> column. Notice
diff --git a/instructor/04-quality-control.html b/instructor/04-quality-control.html
index 1787304d..83835f7d 100644
--- a/instructor/04-quality-control.html
+++ b/instructor/04-quality-control.html
@@ -408,7 +408,7 @@ <h3 class="callout-title">Exercise<a class="anchor" aria-label="anchor" href="#e
 <button class="accordion-button solution-button collapsed" type="button" data-bs-toggle="collapse" data-bs-target="#collapseSolution1" aria-expanded="false" aria-controls="collapseSolution1">
   <h4 class="accordion-header" id="headingSolution1">Show me the solution</h4>
 </button>
-<div id="collapseSolution1" class="accordion-collapse collapse" data-bs-parent="#accordionSolution1" aria-labelledby="headingSolution1">
+<div id="collapseSolution1" class="accordion-collapse collapse" aria-labelledby="headingSolution1" data-bs-parent="#accordionSolution1">
 <div class="accordion-body">
 <p>Click the Sort button on the data tab in Excel. A pop-up will appear.
 Make sure you select <code>Expand the selection</code>.</p>
@@ -461,7 +461,7 @@ <h3 class="callout-title">Exercise<a class="anchor" aria-label="anchor" href="#e
 <button class="accordion-button solution-button collapsed" type="button" data-bs-toggle="collapse" data-bs-target="#collapseSolution2" aria-expanded="false" aria-controls="collapseSolution2">
   <h4 class="accordion-header" id="headingSolution2">Show me the solution</h4>
 </button>
-<div id="collapseSolution2" class="accordion-collapse collapse" data-bs-parent="#accordionSolution2" aria-labelledby="headingSolution2">
+<div id="collapseSolution2" class="accordion-collapse collapse" aria-labelledby="headingSolution2" data-bs-parent="#accordionSolution2">
 <div class="accordion-body">
 <p>Cells that contain non-numerical values are not colored. This
 includes both the cells where the letter “g” was included and the empty
diff --git a/instructor/aio.html b/instructor/aio.html
index 83f35ee4..6671b400 100644
--- a/instructor/aio.html
+++ b/instructor/aio.html
@@ -309,7 +309,7 @@ <h2 class="accordion-header" id="flush-headingTwelve">
         
 <section id="aio-00-intro"><p>Content from <a href="00-intro.html">Introduction</a></p>
 <hr>
-<p>Last updated on 2023-05-03 |
+<p>Last updated on 2024-06-13 |
         
         <a href="https://github.com/datacarpentry/spreadsheet-ecology-lesson/edit/main/episodes/00-intro.md" class="external-link">Edit this page <i aria-hidden="true" data-feather="edit"></i></a></p>
 <p>Estimated time: <i aria-hidden="true" data-feather="clock"></i> 18 minutes</p>
@@ -377,8 +377,8 @@ <h3 id="what-this-lesson-will-not-teach-you">What this lesson will not teach you
 <li>How to do <em>plotting</em> in a spreadsheet</li>
 <li>How to <em>write code</em> in spreadsheet programs</li>
 </ul>
-<p>If you’re looking to do this, a good reference is <a href="https://www.amazon.com/Head-First-Excel-learners-spreadsheets/dp/0596807694/" class="external-link">Head
-First Excel</a>, published by O’Reilly.</p>
+<p>If you’re looking to do this, a good reference is <a href="https://www.amazon.com/Excel-Cookbook-Recipes-Mastering-Microsoft/dp/1098143329/" class="external-link">Excel
+Cookbook</a>, published by O’Reilly.</p>
 <hr>
 </div>
 <div class="section level3">
@@ -698,7 +698,7 @@ <h3 class="callout-title">Exercise<a class="anchor" aria-label="anchor" href="#e
 <button class="accordion-button solution-button collapsed" type="button" data-bs-toggle="collapse" data-bs-target="#collapseSolution1" aria-expanded="false" aria-controls="collapseSolution1">
   <h4 class="accordion-header" id="headingSolution1">Show me the solution</h4>
 </button>
-<div id="collapseSolution1" class="accordion-collapse collapse" data-bs-parent="#accordionSolution1" aria-labelledby="headingSolution1">
+<div id="collapseSolution1" class="accordion-collapse collapse" aria-labelledby="headingSolution1" data-bs-parent="#accordionSolution1">
 <div class="accordion-body">
 <ul>
 <li>Take about 10 minutes to work on this exercise.</li>
@@ -1407,7 +1407,7 @@ <h3 class="callout-title">Exercise<a class="anchor" aria-label="anchor" href="#e
 <button class="accordion-button solution-button collapsed" type="button" data-bs-toggle="collapse" data-bs-target="#collapseSolution1" aria-expanded="false" aria-controls="collapseSolution1">
   <h4 class="accordion-header" id="headingSolution1">Show me the solution</h4>
 </button>
-<div id="collapseSolution1" class="accordion-collapse collapse" aria-labelledby="headingSolution1" data-bs-parent="#accordionSolution1">
+<div id="collapseSolution1" class="accordion-collapse collapse" data-bs-parent="#accordionSolution1" aria-labelledby="headingSolution1">
 <div class="accordion-body">
 <p><img src="../fig/solution_exercise_1_dates.png" class="figure"> {alt=‘dates, exersize
 1’ .output}</p>
@@ -1447,7 +1447,7 @@ <h3 class="callout-title">Exercise<a class="anchor" aria-label="anchor" href="#e
 <button class="accordion-button solution-button collapsed" type="button" data-bs-toggle="collapse" data-bs-target="#collapseSolution2" aria-expanded="false" aria-controls="collapseSolution2">
   <h4 class="accordion-header" id="headingSolution2">Show me the solution</h4>
 </button>
-<div id="collapseSolution2" class="accordion-collapse collapse" aria-labelledby="headingSolution2" data-bs-parent="#accordionSolution2">
+<div id="collapseSolution2" class="accordion-collapse collapse" data-bs-parent="#accordionSolution2" aria-labelledby="headingSolution2">
 <div class="accordion-body">
 <ol style="list-style-type: decimal">
 <li>To get the year, type <code>=YEAR(NOW())</code> into any cell in
@@ -1554,7 +1554,7 @@ <h3 class="callout-title">Exercise<a class="anchor" aria-label="anchor" href="#e
 <button class="accordion-button solution-button collapsed" type="button" data-bs-toggle="collapse" data-bs-target="#collapseSolution3" aria-expanded="false" aria-controls="collapseSolution3">
   <h4 class="accordion-header" id="headingSolution3">Show me the solution</h4>
 </button>
-<div id="collapseSolution3" class="accordion-collapse collapse" aria-labelledby="headingSolution3" data-bs-parent="#accordionSolution3">
+<div id="collapseSolution3" class="accordion-collapse collapse" data-bs-parent="#accordionSolution3" aria-labelledby="headingSolution3">
 <div class="accordion-body">
 <ul>
 <li>Click to the <code>dates</code> tab of the workbook and double-click
@@ -1805,7 +1805,7 @@ <h3 class="callout-title">Exercise<a class="anchor" aria-label="anchor" href="#e
 <button class="accordion-button solution-button collapsed" type="button" data-bs-toggle="collapse" data-bs-target="#collapseSolution1" aria-expanded="false" aria-controls="collapseSolution1">
   <h4 class="accordion-header" id="headingSolution1">Show me the solution</h4>
 </button>
-<div id="collapseSolution1" class="accordion-collapse collapse" data-bs-parent="#accordionSolution1" aria-labelledby="headingSolution1">
+<div id="collapseSolution1" class="accordion-collapse collapse" aria-labelledby="headingSolution1" data-bs-parent="#accordionSolution1">
 <div class="accordion-body">
 <p>Click the Sort button on the data tab in Excel. A pop-up will appear.
 Make sure you select <code>Expand the selection</code>.</p>
@@ -1861,7 +1861,7 @@ <h3 class="callout-title">Exercise<a class="anchor" aria-label="anchor" href="#e
 <button class="accordion-button solution-button collapsed" type="button" data-bs-toggle="collapse" data-bs-target="#collapseSolution2" aria-expanded="false" aria-controls="collapseSolution2">
   <h4 class="accordion-header" id="headingSolution2">Show me the solution</h4>
 </button>
-<div id="collapseSolution2" class="accordion-collapse collapse" data-bs-parent="#accordionSolution2" aria-labelledby="headingSolution2">
+<div id="collapseSolution2" class="accordion-collapse collapse" aria-labelledby="headingSolution2" data-bs-parent="#accordionSolution2">
 <div class="accordion-body">
 <p>Cells that contain non-numerical values are not colored. This
 includes both the cells where the letter “g” was included and the empty
diff --git a/md5sum.txt b/md5sum.txt
index e284cbd2..0e611268 100644
--- a/md5sum.txt
+++ b/md5sum.txt
@@ -4,7 +4,7 @@
 "NEWS.md" "3c9c942da69bda78a1d75c0b240e556e" "site/built/NEWS.md" "2023-05-03"
 "config.yaml" "3aa02348824664a9e25d9d51aa61a7ba" "site/built/config.yaml" "2023-05-03"
 "index.md" "2ba01e088b9368e8b270f9d8eadd89ca" "site/built/index.md" "2023-05-03"
-"episodes/00-intro.md" "8dd7199dab6550bf30dfb92f975194b4" "site/built/00-intro.md" "2023-05-03"
+"episodes/00-intro.md" "1b0d7957625bd8f64260fe313e611f59" "site/built/00-intro.md" "2024-06-13"
 "episodes/01-format-data.md" "9a1688c9814fb367c4e587862e1e92a2" "site/built/01-format-data.md" "2024-03-08"
 "episodes/02-common-mistakes.md" "1696e6806679d772369ee8b58af4f80e" "site/built/02-common-mistakes.md" "2024-06-13"
 "episodes/03-dates-as-data.md" "670409bc5dff1db05acbc9f091518bea" "site/built/03-dates-as-data.md" "2023-05-03"
diff --git a/pkgdown.yml b/pkgdown.yml
index 8580f0ff..779ca87c 100644
--- a/pkgdown.yml
+++ b/pkgdown.yml
@@ -2,5 +2,5 @@ pandoc: 3.1.11
 pkgdown: 2.0.9
 pkgdown_sha: ~
 articles: {}
-last_built: 2024-06-13T22:17Z
+last_built: 2024-06-13T22:43Z