BuddyPress.org

Managed to finally sort it out by myself using the following custom css

.buddypress #buddypress div.dir-search input[type="submit"], .buddypress #buddypress .message-search input[type="submit"], .buddypress #buddypress .item-list-tabs ul li.selected a, .buddypress #buddypress .generic-button a, .buddypress #buddypress .submit input[type="submit"], .buddypress #buddypress .ac-reply-content input[type="submit"], .buddypress #buddypress .standard-form input[type="submit"], .buddypress #buddypress .standard-form .button-nav .current a, .buddypress #buddypress .standard-form .button, .buddypress #buddypress input[type="submit"], .buddypress #buddypress a.accept, .buddypress #buddypress #activate-page .standard-form input[type="submit"], .buddypress #buddypress .standard-form #group-create-body input[type="button"], .post-password-required input[type="submit"] {
	display: none !important;
}

Oh hello Alistair !
I forgot that I had this post pending !
I did find the solution, I detailed it here :

http://blog.oxiane.com/2013/12/20/ajouter-un-bouton-envoyer-un-article-dans-buddypress/

Would you like me to translate it ?
You should find the hook names in the code sections, they(re pretty self explanatory !
Cheers !

Alain

@shanebp. I only have it there until the field is added, then I remove it

“Once functions.php is run once, it will add the Time Zone field to the user profile. Once its been added, you can delete everything except the $zones array (you’ll need it later).”

I’m new to wordpress/buddypress so writing a plugin isn’t going to happen anytime soon, but would love to see it done.

Here’s how I did this.

First, I created the “Time Zone” select box for xProfile by putting the code in the following link into my functions.php file.

http://docs.taptappress.com/buddypress-add-time-zone-list-profile-field/

Once functions.php is run once, it will add the Time Zone field to the user profile. Once its been added, you can delete everything except the $zones array (you’ll need it later).

I then created a new function to look up the users time zone and display the last thread date based on that time zone. Put this in your functions.php file.

function mycustom_get_message_thread_last_post_date() {
	global $messages_template;
	$timezone = mycustom_get_member_timezone();
	if ($timezone != '' ) {	
		$timestamp = '@' . strtotime($messages_template->thread->last_message_date); 
		$dt = new DateTime( $timestamp );
		$dt->setTimeZone(new DateTimeZone($timezone));
		return $dt->format('M j, Y, g:i a'); /* format the displayed timestamp however you want */
	} else {
		return bp_format_time( strtotime( $messages_template->thread->last_message_date ) );
	}
}

function mycustom_get_member_timezone() {
/** put the $zones array from the first step here.  I've left it out to save space in this post **/
   return array_search(bp_get_member_profile_data('field=Time Zone'), $zones);	
}

In a child theme, add/edit /members/single/messages/message-loop.php to use your new custom function. There’s two places you need to do this (inbox and sent).

Replace

<span class="activity"><?php bp_message_thread_last_post_date(); ?></span>

With

<span class="activity"><?php echo mycustom_get_message_thread_last_post_date(); ?></span>

That’s it.

Note: Technically you can do without the array if you want, but I wanted to display the GMT offset to the user instead of ‘US/Alaska’ (for example)

Solved!
The bp-templates/bp-legacy/buddypress/members/index.php file was empty! I restored this and works like a dream.