Rails - sql commands not working with datetime - mysql

Question

I have a strange problem with my web app.
I am trying to build a simple reservation system for a game like "Escape the room". For now I made my own calendar looking a railscast (Calendars revised) for having the dates.
For the possible hours I made a new model and a new table in the database
t.integer "id"
t.datetime "start_time"
t.datetime "end_time"
t.datetime "created_at", null: false
t.datetime "updated_at", null: false
In the view I have something like this:
<%= calendar #date do |date| %>
<%= date.day %>
<table class="table">
<tbody>
<% #hours.each_slice(2) do |hour| %>
<tr>
<% hour.each do |h| %>
<td>
<%= link_to h.start_time.strftime('%H:%M'), new_escape_path(date: date, start_time: h.start_time.strftime('%H:%M'), end_time: h.end_time.strftime('%H:%M')) %>
</td>
<% end %>
</tr>
<% end %>
</tbody>
</table>
<% end %>
And I write these parameters into the database passing them in a form where user can complete other fields manually:
<%= text_field_tag :date, params[:date] %><br>
<%= text_field_tag :start_time, params[:start_time] %> do
<%= text_field_tag :end_time, params[:end_time] %>
The problem is that in the view I want to show only the hours which are not reserved yet, which means that they are not in the escapes table.
When in the console I write
Escape.all
I have something like:
#<Escape id: 1, date: "2015-08-11 00:00:00", start_time: "2015-08-10 08:30:00", end_time: nil, user_id: nil, created_at: "2015-08-10 15:26:14", updated_at: "2015-08-10 15:26:14">
but when I write
Escape.all.where(date: "2015-08-11 00:00:00")
it returns an empty record
#<ActiveRecord::Relation []>
I tried also to insert something like this in the view, but it's not working:
<% if Escape.where(["date = ? and start_time = ?", "#{date}", "#{h}"])%>
<%= h.start_time.strftime('%H:%M') %>
<% else %>
<%= link_to h.start_time.strftime('%H:%M'), new_escape_path(date: date, start_time: h.start_time.strftime('%H:%M'), end_time: h.end_time.strftime('%H:%M')) %>
<% end %>
Do you have any ideas? What am I doing wrong?