app/views/sensors/_filter_form.erb
<%= form_tag '', method: :get, class: 'form-horizontal' do %>
<div class="form-group">
<%= label_tag :from, t('from'), class: 'control-label col-sm-3' %>
<div class="col-sm-9">
<%= date_field_tag :from, @from, class: 'form-control' %>
</div>
</div>
<div class="form-group">
<%= label_tag :to, t('to'), class: 'control-label col-sm-3' %>
<div class="col-sm-9">
<%= date_field_tag :to, @to, class: 'form-control' %>
</div>
</div>
<%= button_tag type: 'submit', class: 'btn btn-primary btn-block' do %>
<i class="glyphicon glyphicon-filter"></i> <%= t('sensor.filter') %>
<% end %>
<% end %>