--- a/index.xhtml
+++ b/index.xhtml
@@ -104,7 +104,7 @@ Enter your nickname, so people you know 
 <div class="col-sm-8">
 <p>
 <label>Full name<br/>
-<input id="vcard-fullname" disabled=""/></label><br/>
+<input id="vcard-fn" disabled=""/></label><br/>
 Enter your name, so people you know can recognize you.
 </p>
 <p>
@@ -113,6 +113,10 @@ Enter your name, so people you know can 
 This can be used if you forget your password.
 </p>
 <p>
+<label>Birthday<br/>
+<input id="vcard-bday" type="date" disabled=""/></label>
+</p>
+<p>
 <label>Who can see your vCard?<br/>
 <select id="vcard-access">
 <option value="open">Anyone</option>

--- a/vcard.js
+++ b/vcard.js
@@ -2,8 +2,9 @@
 
 function initVCard(connection) {
     const vcard_access = document.getElementById('vcard-access');
-    const vcard_fullname = document.getElementById('vcard-fullname');
+    const vcard_fn = document.getElementById('vcard-fn');
     const vcard_email = document.getElementById('vcard-email');
+    const vcard_bday = document.getElementById('vcard-bday');
     const spinner_img = document.getElementById('vcard-spinner');
     const access_spinner_img = document.getElementById('vcard-access-spinner');
 
@@ -27,36 +28,46 @@ function initVCard(connection) {
 
         vcard_data.fn = parseXPathText(vcard, './vcard4:fn/vcard4:text');
         vcard_data.email = parseXPathText(vcard, './vcard4:email/vcard4:text');
+        vcard_data.bday = parseXPathText(vcard, './vcard4:bday/vcard4:date');
 
-        vcard_fullname.value = vcard_data.fn;
-        vcard_fullname.disabled = false;
+        vcard_fn.value = vcard_data.fn;
+        vcard_fn.disabled = false;
         vcard_email.value = vcard_data.email;
         vcard_email.disabled = false;
+        vcard_bday.value = vcard_data.bday;
+        vcard_bday.disabled = false;
         hideSpinner(spinner_img);
     }
 
     function onVCard4RetrievalError(string)
     {
         console.log('Failed to retrieve vCard4: ' + string);
-        vcard_fullname.disabled = false;
+        vcard_fn.disabled = false;
         vcard_email.disabled = false;
+        vcard_bday.disabled = false;
         hideSpinner(spinner_img);
     }
 
     function setVCard4() {
         // TODO: avoid overriding fields we don’t understand.
         const iq = $iq({type: 'set'})
-            .c('vcard', {xmlns: 'urn:ietf:params:xml:ns:vcard-4.0'})
-                .c('fn')
-                    .c('text').t(vcard_fullname.value).up().up()
-                .c('email')
-                    .c('text').t(vcard_email.value).up().up()
+            .c('vcard', {xmlns: 'urn:ietf:params:xml:ns:vcard-4.0'});
+        if (vcard_fn.value)
+            iq.c('fn')
+                .c('text').t(vcard_fn.value).up().up();
+        if (vcard_email.value)
+            iq.c('email')
+                .c('text').t(vcard_email.value).up().up();
+        if (vcard_bday.value)
+            iq.c('bday')
+                .c('date').t(vcard_bday.value).up().up();
         connection.sendIQ(iq, onVCard4Changed, onVCard4ChangeError.bind(null, 'coucou'));
         displaySpinner(spinner_img);
     }
 
-    vcard_fullname.addEventListener('blur', setVCard4);
+    vcard_fn.addEventListener('blur', setVCard4);
     vcard_email.addEventListener('blur', setVCard4);
+    vcard_bday.addEventListener('change', setVCard4);
 
     function onVCard4Changed(result_iq)
     {