Date and Month in single select box rails...last six months and last one year...

in controller:

@date = Date.today
@months = []
(0..17).each do |m|
@months << [@date.prev_month(m).strftime("%b, %Y"), @date.prev_month(m)]
end

In ERB:

<%= select_tag "month_year", options_for_select(@months) %>


In Order to get next 6 months and next year months:

@date = Date.today
@months = []
(0..17).each do |m|
  @months << [@date.next_month(m).strftime("%b %Y"), @date.next_month(m)]
end