Calendar for the current month

home.css.scss

// Place all the styles related to the home controller here.
// They will automatically be included in application.css.
// You can use Sass (SCSS) here: http://sass-lang.com/
#monthName {
  text-align: center;
  position: absolute;
  top: 0;
  display: inline;
  a {
    text-decoration: none;
    color: blue;
    &:hover {
      color: red;
      text-decoration: underline;
    }
  }
}

table.calendar {
  margin-top: 5em;
  th {
    background-color: lightgrey;
  }
  td {
    font-family: Georgia, serif;
    text-align: right;
    vertical-align: top;
    width: 100px;
    height: 100px;
    &span.day {
      position: relative;
      top: 0.5em;
      right: 0.5em;
      margin-top: 2em;
      font-size: 1.5em;
    }
    &.weekend {
      background-color: lightgrey;
    }
    &.today {
      background-color: yellow;
    }
  }
}

home.js.coffee

# Place all the behaviors and hooks related to the matching controller here.
# All this logic will automatically be available in application.js.
# You can use CoffeeScript in this file: http://jashkenas.github.com/coffee-script/
$ ->
  tableWidth = $('table').width()
  $('h1#monthName').css('width',tableWidth)

home_controller.rb

class HomeController < ApplicationController
  def index
    current_year  = (params[:year ] || Date.today.year )
    current_month = (params[:month] || Date.today.month)
    @current_date  = "#{current_year}-#{current_month}-#{Date.today.day}".to_date

    @days_in_month = []
    @days_in_month[@current_date.beginning_of_month.wday] = (@current_date.beginning_of_month..@current_date.end_of_month).to_a
    @days_in_month = @days_in_month.flatten.in_groups_of(7, false)

    @beginning_of_month_blanks_count = @current_date.beginning_of_month.wday
    @days_in_month[0].compact!
    
    @end_of_month_blanks_count = (6 - @current_date.end_of_month.wday)
    puts @days_in_month.inspect
  end
end

home_helper.rb

module HomeHelper
  def multiclass(*args)

    if args[0].is_a?(Hash)
      args[0] = args[0].to_a.collect do |key,value|
        key.to_s if value
      end.compact
    end
    
    args.join(" ")

  end
  
  def root_path_month_year(math)
    date = @current_date + math
    root_path(month: date.month, year: date.year)
  end
end

index.html.haml

%h1#monthName
  = link_to raw("«"), root_path_month_year(-1.month)
  = @current_date.strftime("%B")
  = link_to raw("»"), root_path_month_year(1.month)
  = link_to raw("«"), root_path_month_year(-1.year)
  = @current_date.strftime("%Y")
  = link_to raw("»"), root_path_month_year(1.year)

%table.calendar{border: 1}
  %tr
    - Date::DAYNAMES.each do |day_of_week|
      %th= day_of_week
    - @days_in_month.each_with_index do |week,index|
      %tr
        - if @beginning_of_month_blanks_count > 0 && index == 0
          %td{colspan: @beginning_of_month_blanks_count}  

        - week.each do |date|
          %td{class: multiclass(today: date.today?, weekend: (date.sunday? || date.saturday?))}
            %span.day=raw date ? date.day : " "

        - if index == (@days_in_month.count)
          %td{colspan: @end_of_month_blanks_count}