update

src/_sass/gnome-shell/widgets/_panel.scss

@@ -61,10 +61,11 @@ $panel_button_hpadding: ($panel_height - 16px) / 2;
     &.clock-display {
       -natural-hpadding: 0 !important;
       -minimum-hpadding: 0 !important;
+      padding: 0 !important;
+      spacing: 0 !important;
 
       .clock {
         border-radius: if($corner_style == 'circular', $circular-radius, $material-radius + $space-size / 2);
-        margin: 0 $space-size * 2 !important;
       }
     }
 

src/gnome-shell/shell-40-0/gnome-shell-Compact.css

@@ -1948,11 +1948,12 @@ StScrollBar StButton#vhandle:active, StScrollBar StButton#hhandle:active {
 #panel .panel-button.clock-display {
   -natural-hpadding: 0 !important;
   -minimum-hpadding: 0 !important;
+  padding: 0 !important;
+  spacing: 0 !important;
 }
 
 #panel .panel-button.clock-display .clock {
   border-radius: 9999px;
-  margin: 0 8px !important;
 }
 
 #panel .panel-button:hover {

src/gnome-shell/shell-40-0/gnome-shell-Dark-Compact.css

@@ -1948,11 +1948,12 @@ StScrollBar StButton#vhandle:active, StScrollBar StButton#hhandle:active {
 #panel .panel-button.clock-display {
   -natural-hpadding: 0 !important;
   -minimum-hpadding: 0 !important;
+  padding: 0 !important;
+  spacing: 0 !important;
 }
 
 #panel .panel-button.clock-display .clock {
   border-radius: 9999px;
-  margin: 0 8px !important;
 }
 
 #panel .panel-button:hover {

src/gnome-shell/shell-40-0/gnome-shell-Dark.css

@@ -1948,11 +1948,12 @@ StScrollBar StButton#vhandle:active, StScrollBar StButton#hhandle:active {
 #panel .panel-button.clock-display {
   -natural-hpadding: 0 !important;
   -minimum-hpadding: 0 !important;
+  padding: 0 !important;
+  spacing: 0 !important;
 }
 
 #panel .panel-button.clock-display .clock {
   border-radius: 9999px;
-  margin: 0 12px !important;
 }
 
 #panel .panel-button:hover {

src/gnome-shell/shell-40-0/gnome-shell.css

@@ -1948,11 +1948,12 @@ StScrollBar StButton#vhandle:active, StScrollBar StButton#hhandle:active {
 #panel .panel-button.clock-display {
   -natural-hpadding: 0 !important;
   -minimum-hpadding: 0 !important;
+  padding: 0 !important;
+  spacing: 0 !important;
 }
 
 #panel .panel-button.clock-display .clock {
   border-radius: 9999px;
-  margin: 0 12px !important;
 }
 
 #panel .panel-button:hover {

src/gnome-shell/shell-42-0/gnome-shell-Compact.css

@@ -2312,11 +2312,12 @@ StScrollBar StButton#vhandle:active, StScrollBar StButton#hhandle:active {
 #panel .panel-button.clock-display {
   -natural-hpadding: 0 !important;
   -minimum-hpadding: 0 !important;
+  padding: 0 !important;
+  spacing: 0 !important;
 }
 
 #panel .panel-button.clock-display .clock {
   border-radius: 9999px;
-  margin: 0 8px !important;
 }
 
 #panel .panel-button:hover {

src/gnome-shell/shell-42-0/gnome-shell-Dark-Compact.css

@@ -2316,11 +2316,12 @@ StScrollBar StButton#vhandle:active, StScrollBar StButton#hhandle:active {
 #panel .panel-button.clock-display {
   -natural-hpadding: 0 !important;
   -minimum-hpadding: 0 !important;
+  padding: 0 !important;
+  spacing: 0 !important;
 }
 
 #panel .panel-button.clock-display .clock {
   border-radius: 9999px;
-  margin: 0 8px !important;
 }
 
 #panel .panel-button:hover {

src/gnome-shell/shell-42-0/gnome-shell-Dark.css

@@ -2316,11 +2316,12 @@ StScrollBar StButton#vhandle:active, StScrollBar StButton#hhandle:active {
 #panel .panel-button.clock-display {
   -natural-hpadding: 0 !important;
   -minimum-hpadding: 0 !important;
+  padding: 0 !important;
+  spacing: 0 !important;
 }
 
 #panel .panel-button.clock-display .clock {
   border-radius: 9999px;
-  margin: 0 12px !important;
 }
 
 #panel .panel-button:hover {

src/gnome-shell/shell-42-0/gnome-shell.css

@@ -2312,11 +2312,12 @@ StScrollBar StButton#vhandle:active, StScrollBar StButton#hhandle:active {
 #panel .panel-button.clock-display {
   -natural-hpadding: 0 !important;
   -minimum-hpadding: 0 !important;
+  padding: 0 !important;
+  spacing: 0 !important;
 }
 
 #panel .panel-button.clock-display .clock {
   border-radius: 9999px;
-  margin: 0 12px !important;
 }
 
 #panel .panel-button:hover {