A patch for Android’s DeskClock, adding seconds to the display. Partially broken and not really finalized, but AOSP apps are a pain to build.

DeskClock-seconds.patch

diff --git a/res/layout/main_clock_frame.xml b/res/layout/main_clock_frame.xml
index ba51c2d..fdc9f05 100644
--- a/res/layout/main_clock_frame.xml
+++ b/res/layout/main_clock_frame.xml
@@ -41,7 +41,7 @@
         <TextClock
             android:id="@+id/digital_clock"
             android:format12Hour="@string/main_clock_12_hours_format"
-            android:format24Hour="@string/clock_24_hours_format"
+            android:format24Hour="@string/clock_24_hours_format_sec"
             android:layout_gravity="center"
             android:layout_width="wrap_content"
             android:layout_height="wrap_content"
@@ -49,8 +49,8 @@
             android:layout_marginBottom="@dimen/bottom_text_spacing_digital"
             android:singleLine="true"
             android:ellipsize="none"
-            style="@style/big_thin"
-            android:textSize="@dimen/digital_main_clock_text_size"
+            style="@style/big_thin_plus"
+            android:textSize="@dimen/digital_main_clock_text_size_plus"
             android:textColor="@color/clock_white" />
 
     </FrameLayout>
diff --git a/res/values/dimens.xml b/res/values/dimens.xml
index 0c30820..f745022 100644
--- a/res/values/dimens.xml
+++ b/res/values/dimens.xml
@@ -47,6 +47,7 @@
     <dimen name="digital_world_clock_text_size">60dp</dimen>
     <dimen name="digital_world_clock_ampm_text_size">14dp</dimen>
     <dimen name="digital_main_clock_text_size">120dp</dimen>
+    <dimen name="digital_main_clock_text_size_plus">85dp</dimen>
     <dimen name="digital_screensaver_clock_text_size">100dp</dimen>
 
     <!-- Analog clock size in the the screen saver -->
@@ -79,6 +80,7 @@
     <dimen name="circletimer_marker_size">16dip</dimen>
 
     <dimen name="big_font_size">120dp</dimen>
+    <dimen name="big_font_size_plus">85dp</dimen>
     <dimen name="small_font_size">48sp</dimen>
     <dimen name="medium_font_size">60dp</dimen>
     <dimen name="label_font_size">14sp</dimen>
diff --git a/res/values/strings.xml b/res/values/strings.xml
index 134f700..87acc36 100644
--- a/res/values/strings.xml
+++ b/res/values/strings.xml
@@ -805,6 +805,7 @@
 
     <!-- format strings for clocks -->
     <string name="clock_24_hours_format" translatable="false">kk&#58;mm</string>
+    <string name="clock_24_hours_format_sec" translatable="false">kk&#58;mm&#58;ss</string>
     <string name="main_widget_12_hours_format" translatable="false">h&#58;mm</string>
     <!-- Font size for AM/PM should match widget_label_font_size -->
     <string name="wc_widget_12_hours_format" translatable="false">h&#58;mm&#8202;<b><font size="14" face="sans-serif-condensed">a</font></b></string>
diff --git a/res/values/styles.xml b/res/values/styles.xml
index 9a2c149..2e5e184 100644
--- a/res/values/styles.xml
+++ b/res/values/styles.xml
@@ -208,6 +208,11 @@
         <item name="android:fontFamily">sans-serif-thin</item>
     </style>
 
+    <style name="big_thin_plus">
+        <item name="android:textSize">@dimen/big_font_size_plus</item>
+        <item name="android:fontFamily">sans-serif-thin</item>
+    </style>
+
     <style name="widget_big_thin" parent="big_thin">
         <item name="android:textSize">@dimen/widget_big_font_size</item>
     </style>
diff --git a/src/com/android/deskclock/ClockFragment.java b/src/com/android/deskclock/ClockFragment.java
index 222ec4b..c35c9ab 100644
--- a/src/com/android/deskclock/ClockFragment.java
+++ b/src/com/android/deskclock/ClockFragment.java
@@ -78,7 +78,7 @@ public class ClockFragment extends DeskClockFragment implements OnSharedPreferen
                     // reload the cities list with new localized names
                     if (action.equals(Intent.ACTION_LOCALE_CHANGED)) {
                         if (mDigitalClock != null) {
-                            Utils.setTimeFormat(
+                            Utils.setTimeFormatPLUS(
                                    (TextClock)(mDigitalClock.findViewById(R.id.digital_clock)),
                                    (int)context.getResources().
                                            getDimension(R.dimen.bottom_text_size));
@@ -190,7 +190,7 @@ public class ClockFragment extends DeskClockFragment implements OnSharedPreferen
 
         mDigitalClock = mClockFrame.findViewById(R.id.digital_clock);
         mAnalogClock = mClockFrame.findViewById(R.id.analog_clock);
-        Utils.setTimeFormat((TextClock)(mDigitalClock.findViewById(R.id.digital_clock)),
+        Utils.setTimeFormatPLUS((TextClock)(mDigitalClock.findViewById(R.id.digital_clock)),
                 (int)getResources().getDimension(R.dimen.bottom_text_size));
         View footerView = inflater.inflate(R.layout.blank_footer_view, mList, false);
         footerView.setBackgroundResource(R.color.blackish);
diff --git a/src/com/android/deskclock/Utils.java b/src/com/android/deskclock/Utils.java
index 21257f9..0de8c8d 100644
--- a/src/com/android/deskclock/Utils.java
+++ b/src/com/android/deskclock/Utils.java
@@ -506,6 +506,13 @@ public class Utils {
             clock.setFormat24Hour(get24ModeFormat());
         }
     }
+
+    public static void setTimeFormatPLUS(TextClock clock, int amPmFontSize) {
+        if (clock != null) {
+            clock.setFormat24Hour(get24ModeFormatPLUS());
+        }
+    }
+
     /***
      * @param amPmFontSize - size of am/pm label (label removed is size is 0).
      * @return format string for 12 hours mode time
@@ -539,6 +546,11 @@ public class Utils {
         return DateFormat.getBestDateTimePattern(Locale.getDefault(), skeleton);
     }
 
+    public static CharSequence get24ModeFormatPLUS() {
+        String skeleton = "Hms";
+        return DateFormat.getBestDateTimePattern(Locale.getDefault(), skeleton);
+    }
+
     public static CityObj[] loadCitiesFromXml(Context c) {
         final Collator collator = Collator.getInstance();
         Resources r = c.getResources();