diff --git a/html/admin.html b/html/admin.html
index 0ad8a37..40f97b1 100755
--- a/html/admin.html
+++ b/html/admin.html
@@ -213,6 +213,7 @@
               <div class="mb-3">
                 <label for="sys_local_time" class="form-label">System time (local)</label>
                 <input type="text" class="form-control" id="sys_local_time" disabled>
+                <small class="text-muted">Horloge Linux du Raspberry Pi. Se synchronise via internet (NTP).</small>
               </div>
 
               <div class="mb-3">
@@ -223,12 +224,14 @@
               <div class="mb-3">
                 <label for="RTC_utc_time" class="form-label">RTC time (UTC)</label>
                 <input type="text" class="form-control" id="RTC_utc_time" disabled>
+                <small class="text-muted">Module DS3231 avec pile de sauvegarde. Garde l'heure meme hors tension.</small>
               </div>
 
 
               <div id="alert_container"></div>
 
-              <h5 class="mt-4">Set RTC</h5>
+              <h5 class="mt-4">Synchroniser le RTC</h5>
+              <small class="text-muted d-block mb-2">Met a jour l'horloge RTC pour qu'elle reste precise sans internet.</small>
 
               <button type="submit" class="btn btn-primary mb-1" onclick="set_RTC_withNTP()">WiFi (NTP) </button>
               <button type="submit" class="btn btn-primary mb-1" onclick="set_RTC_withBrowser()">Browser time </button>