diff --git a/src/Templates/highlight.php/yaml.json b/src/Templates/highlight.php/yaml.json
index a8b796b..3db70a8 100644
--- a/src/Templates/highlight.php/yaml.json
+++ b/src/Templates/highlight.php/yaml.json
@@ -79,6 +79,10 @@
                 "literal": "true false yes no null"
             }
         },
+        {
+            "className": "number",
+            "begin": "\\b([0-9][0-9][0-9][0-9])-([0-9][0-9]?)-([0-9][0-9]?)(([Tt]|[ \\t]+)([0-9][0-9]?):([0-9][0-9]):([0-9][0-9])(\\.([0-9]*))?([ \\t]*(Z|([-+])([0-9][0-9]?)(:([0-9][0-9]))?))?)?\\b"
+        },
         {
             "className": "number",
             "begin": "(-?)(\\b0[xX][a-fA-F0-9_]+|(\\b\\d[\\d_]*(\\.[\\d_]*)?|\\.\\d[\\d_]*)([eE][-+]?\\d[\\d_]*)?)\\b"
diff --git a/tests/fixtures/expected/blocks/code-blocks/yaml.html b/tests/fixtures/expected/blocks/code-blocks/yaml.html
index 9af8127..2de3b7b 100644
--- a/tests/fixtures/expected/blocks/code-blocks/yaml.html
+++ b/tests/fixtures/expected/blocks/code-blocks/yaml.html
@@ -1,11 +1,15 @@
-<div translate="no" data-loc="6" class="notranslate codeblock codeblock-length-sm codeblock-yaml">
+<div translate="no" data-loc="10" class="notranslate codeblock codeblock-length-md codeblock-yaml">
     <div class="codeblock-scroll">
         <pre class="codeblock-lines">1
 2
 3
 4
 5
-6</pre>
+6
+7
+8
+9
+10</pre>
         <pre class="codeblock-code">
             <code>
                 <span class="hljs-comment"># some code</span>
@@ -18,6 +22,14 @@
                 <span class="hljs-number">3.14159_26535_89793</span>
                 <span class="hljs-attr">hex_words:</span>
                 <span class="hljs-number">0x_CAFE_F00D</span>
+                <span class="hljs-attr">canonical:</span>
+                <span class="hljs-number">2001-12-15T02:59:43.1Z</span>
+                <span class="hljs-attr">iso8601:</span>
+                <span class="hljs-number">2001-12-14t21:59:43.10-05:00</span>
+                <span class="hljs-attr">spaced:</span>
+                <span class="hljs-number">2001-12-14 21:59:43.10 -5</span>
+                <span class="hljs-attr">date:</span>
+                <span class="hljs-number">2002-12-14</span>
             </code>
         </pre>
     </div>
diff --git a/tests/fixtures/source/blocks/code-blocks/yaml.rst b/tests/fixtures/source/blocks/code-blocks/yaml.rst
index 0bba2a6..f56652d 100644
--- a/tests/fixtures/source/blocks/code-blocks/yaml.rst
+++ b/tests/fixtures/source/blocks/code-blocks/yaml.rst
@@ -6,3 +6,7 @@
         long_number: 10_000_000_000
         pi: 3.14159_26535_89793
         hex_words: 0x_CAFE_F00D
+        canonical: 2001-12-15T02:59:43.1Z
+        iso8601: 2001-12-14t21:59:43.10-05:00
+        spaced: 2001-12-14 21:59:43.10 -5
+        date: 2002-12-14