[Samsung Galaxy Nexus] nikosrs4:
This mod will let the date always displaying in statusbar, like the clock does..check the screenshot. I also removed date from notification header, since it's already in statusbar.

For the center date in AOKP go to the end of the post.

Always backup before you try anything!

You have to decompile(apk manager does it) SystemUI.apk.

Go to file SystemUI.apk\res\layout\status_bar.xml

find the line 15

<com.android.systemui.statusbar.policy.Clock android:textAppearance="@style/TextAppearance.StatusBar.Clock" android:gravity="left|center" android:id="@id/clock" android:paddingLeft="4.0dip" android:layout_width="wrap_content" android:layout_height="fill_parent" android:singleLine="true" />

place on top of it the line

<com.android.systemui.statusbar.policy.DateView android:textAppearance="@style/TextAppearance.StatusBar.Date" android:gravity="left|center" android:id="@id/date" android:paddingLeft="4.0dip" android:layout_width="wrap_content" android:layout_height="fill_parent" android:singleLine="true" android:layout_toLeftOf="@id/clock" />

so it will look like that

</LinearLayout>
[COLOR="Red"]<com.android.systemui.statusbar.policy.DateView android:textAppearance="@style/TextAppearance.StatusBar.Date" android:gravity="left|center" android:id="@id/date" android:paddingLeft="4.0dip" android:layout_width="wrap_content" android:layout_height="fill_parent" android:singleLine="true" android:layout_toLeftOf="@id/clock" />
<com.android.systemui.statusbar.policy.Clock android:textAppearance="@style/TextAppearance.StatusBar.Clock" android:gravity="left|center" android:id="@id/clock" android:paddingLeft="4.0dip" android:layout_width="wrap_content" android:layout_height="fill_parent" android:singleLine="true" />[/COLOR]
</LinearLayout>

now here, I set the

android:paddingLeft="4.0dip"

with the same value in both clock and date, so they have the same space at the left.

With this setup, you will always see date and then clock at the right of the statusbar(I haven't test something else yet).

if you want to delete the date from the notification header, do the following

in the file SystemUI.apk\res\layout\status_bar_expanded.xml delete the following line

<com.android.systemui.statusbar.policy.DateView android:textAppearance="@style/TextAppearance.StatusBar.Date" android:gravity="left|center" android:id="@id/date" android:paddingLeft="16.0dip" android:layout_width="wrap_content" android:layout_height="fill_parent" android:singleLine="true" android:layout_alignParentLeft="true" />

and in the line

<ImageView android:id="@id/settings_button" android:paddingLeft="8.0dip" android:paddingRight="8.0dip" android:layout_width="wrap_content" android:layout_height="fill_parent" android:src="@drawable/ic_notify_quicksettings" android:layout_toRightOf="@id/date" android:contentDescription="@string/accessibility_settings_button" />

replace the

android:layout_toRightOf="@id/date"

with the following(it maybe not crucial, but I did it)

android:layout_alignParentLeft="true"

it should look something like that

the text size is probably looking different between date and clock, so in the file SystemUI.apk\res\values\styles.xml is the text size of both.

clock

<style name="TextAppearance.StatusBar.Clock" parent="@android:style/TextAppearance.StatusBar.Icon">
<item name="android:textSize">16.0dip</item>
<item name="android:textStyle">normal</item>
<item name="android:textColor">@android:color/holo_blue_light</item>
</style>

and date

<style name="TextAppearance.StatusBar.Date" parent="@android:style/TextAppearance.StatusBar.Icon">
<item name="android:textSize">16.0sp</item>
<item name="android:textStyle">normal</item>
<item name="android:textColor">@android:color/holo_blue_light</item>
</style>

I changed both with

[COLOR="Red"]<item name="android:textSize">[B]14.0sp[/B]</item>[/COLOR]

Center Date in AOKP roms

although if you enable every statusbar icon(bt, vibrate,alarm,wifi etc) it will look messy cause the clock overlapse the icons.

since AOKP rom has an option to set the clock in the center, it's quite easy to have the date in that order too.

in file SystemUI.apk\res\layout\status_bar.xml copy&delete or cut the line

<com.android.systemui.statusbar.policy.DateView android:textAppearance="@style/TextAppearance.StatusBar.Date" android:gravity="left|center" android:id="@id/date" android:paddingLeft="4.0dip" android:layout_width="wrap_content" android:layout_height="fill_parent" android:singleLine="true" android:layout_toLeftOf="@id/clock" />

and place it in top of (watch the centerclock, not just clock)

<com.android.systemui.statusbar.policy.[COLOR="Red"]CenterClock[/COLOR] android:textAppearance="@style/TextAppearance.StatusBar.Clock" android:gravity="center" android:id="@id/center_clock" android:paddingLeft="4.0dip" android:layout_width="wrap_content" android:layout_height="fill_parent" android:singleLine="true" />

so it will look like that

<LinearLayout android:gravity="center" android:orientation="horizontal" android:id="@id/center_clock_layout" android:layout_width="fill_parent" android:layout_height="fill_parent">
<com.android.systemui.statusbar.policy.DateView android:textAppearance="@style/TextAppearance.StatusBar.Date" android:gravity="left|center" android:id="@id/date" android:paddingLeft="4.0dip" android:layout_width="wrap_content" android:layout_height="fill_parent" android:singleLine="true" android:layout_toLeftOf="@id/center_clock" />
<com.android.systemui.statusbar.policy.CenterClock android:textAppearance="@style/TextAppearance.StatusBar.Clock" android:gravity="center" android:id="@id/center_clock" android:paddingLeft="4.0dip" android:layout_width="wrap_content" android:layout_height="fill_parent" android:singleLine="true" />
</LinearLayout>

now in the end of the line you cut/copied change the "@id/clock" into "@id/center_clock", so it will look like that

android:layout_toLeftOf="@id/center_clock"

now you're good to go, it will look like that(it won't be in italic, I just changed it) and choose center clock in ROM control options in settings, otherwise you'll have center date and clock at the right which is also nice :p

I hope I didn't forget anything :)

Recompile and push it/flash it.

submit your comments and mods, left, center date or whatever :)