diff --git a/frontend/apps/reader/modules/readercoptlistener.lua b/frontend/apps/reader/modules/readercoptlistener.lua
index 16105b390..87c7ca9df 100644
--- a/frontend/apps/reader/modules/readercoptlistener.lua
+++ b/frontend/apps/reader/modules/readercoptlistener.lua
@@ -40,6 +40,8 @@ function ReaderCoptListener:onReadSettings(config)
     self.ui.document._document:setIntProperty("window.status.battery.percent", self.battery_percent)
     self.ui.document._document:setIntProperty("window.status.pos.percent", self.reading_percent)
 
+    self:onTimeFormatChanged()
+
     local status_line = config:readSetting("copt_status_line") or G_reader_settings:readSetting("copt_status_line") or 1
     self.ui:handleEvent(Event:new("SetStatusLine", status_line, true))
 end
@@ -48,6 +50,10 @@ function ReaderCoptListener:onSetFontSize(font_size)
     self.document.configurable.font_size = font_size
 end
 
+function ReaderCoptListener:onTimeFormatChanged()
+    self.ui.document._document:setIntProperty("window.status.clock.12hours", G_reader_settings:isTrue("twelve_hour_clock") and 1 or 0)
+end
+
 function ReaderCoptListener:setAndSave(setting, property, value)
     self.ui.document._document:setIntProperty(property, value)
     G_reader_settings:saveSetting(setting, value)
diff --git a/frontend/ui/elements/common_settings_menu_table.lua b/frontend/ui/elements/common_settings_menu_table.lua
index 6a96504d0..4e9b233c4 100644
--- a/frontend/ui/elements/common_settings_menu_table.lua
+++ b/frontend/ui/elements/common_settings_menu_table.lua
@@ -81,6 +81,7 @@ common_settings.time = {
         end,
         callback = function()
             G_reader_settings:flipNilOrFalse("twelve_hour_clock")
+            UIManager:broadcastEvent(Event:new("TimeFormatChanged"))
         end,
         }
     }