Rails 4 x Bootstrap 3 Datetimepicker: replace default datetime_select with datetimepicker - ruby-on-rails

Question

In my Rails 4 app, which already uses Bootstrap 3, I just added Datetimepicker by eonasdan.
I carefully followed the instructions offered here and there to install the plugin.
Here is my setup:
Gemfile
gem 'momentjs-rails'
gem 'bootstrap3-datetimepicker-rails'
application.js
//= require jquery
//= require jquery.turbolinks
//= require jquery_ujs
//= require bootstrap
//= require bootstrap/dropdown
//= require moment
//= require bootstrap-datetimepicker
//= require turbolinks
//= require_tree .
application.scss
#import "bootstrap-sprockets";
#import "bootstrap";
#import 'bootstrap/theme';
#import 'bootstrap-datetimepicker';
#import "font-awesome-sprockets";
#import "font-awesome";
#import "simple_calendar";
#import "custom.scss";
#import "custom/**/*"
And I do have restarted my server.
Now, I am trying to use the plugin in my Posts#New and Posts#Edit views form, to replace the current datetime_select field:
<div class="field">
<%= f.label :date, "DATE" %>
<%= f.datetime_select :date %>
</div>
This is where I am after my first attempt:
<div class="form-group">
<div class='input-group date' id='datetimepicker'>
<%= f.label :date, "DATE & TIME" %>
<%= f.text_field :date, :class => "form-control"%>
<span class="input-group-addon">
<span class="glyphicon glyphicon-calendar"></span>
</span>
</div>
<script type="text/javascript">
$(function () {
$('#datetimepicker').datetimepicker();
});
</script>
</div>
Which gives me the following elements in the view:
Although the design is far from perfect, for now, this is not what I am concerned about.
The real problem is that, when I create a post, the date attribute (which is a datetime data type) is set to nil, instead of the value chosen in the datetimepicker.
I looked for similar situations online, and the closest I have found is this Stack Overflow question.
Unfortunately, it is based on slim forms, and I don't know how to "translate" them into regular forms, to be used in a erb.html file.
Any idea of what is wrong with my code?
—————
UPDATE: I have found a way that is actually saving the date to the database when the post is created:
<div class="form-group" id="post_date_time">
<%= f.label :date, "DATE & TIME" %>
<div class='input-group date' id='datetimepicker'>
<%= f.text_field :date, :class => "form-control"%>
<span class="input-group-addon">
<span class="glyphicon glyphicon-calendar"></span>
</span>
</div>
</div>
<script type="text/javascript">
$(function () {
$('#datetimepicker').datetimepicker();
});
</script>
However, it does not seem to work properly on the edit form, since I don't get the datetimepicker populated with the date of the post. Am I missing something here?
—————

Answer 1

To get the datetime populated on your edit page you can do this in the javascript setup:
<script type="text/javascript">
$(function () {
$('#datetimepicker').datetimepicker({
defaultDate: "<%= #post.date %>",
format: "YYYY-MM-DD hh:mm a Z"
});
});
</script>
I have the working code here: Github - Rails Datetimepicker Example