gistfile1.erb

<div class="select-date-period" id="date-popup" style="display: none;">
  <ul class="dates">
    <li class="selected" data-start="<%= Date.today %>" data-end="<%= Date.today %>">
      <span><%= t :today %></span></li>
    <li class="" data-start="<%= Date.yesterday %>" data-end="<%= Date.today %>">
      <span><%= t :yesterday %></span></li>
    <li class="" data-start="<%= 7.days.ago.to_date %>" data-end="<%= Date.today %>">
      <span><%= t :last_7_days %></span></li>
    <li class="" data-start="<%= 30.days.ago.to_date %>" data-end="<%= Date.today %>">
      <span><%= t :last_30_days %></span></li>
    <li class="" data-start="<%= Date.today.beginning_of_month %>" data-end="<%= Date.today %>">
      <span><%= t :this_month %></span></li>
    <li class="" data-start="<%= Date.today.beginning_of_month.prev_month %>" data-end="<%= Date.today.beginning_of_month - 1.day %>">
      <span><%= t :last_month %></span></li>
    <li class="custom_range" data-start="" data-end="">
      <span><%= t :custom_range %></span></li>
  </ul>

gistfile2.slim

ul.dates
  li.selected data-end=Date.today data-start=Date.today 
    span= t :today
  li data-end=Date.today data-start=Date.yesterday 
    span= t :yesterday
  li data-end=Date.today data-start=7.days.ago.to_date 
    span= t :last_7_days
  li data-end=Date.today data-start=30.days.ago.to_date 
    span= t :last_30_days
  li data-end=Date.today data-start=Date.today.beginning_of_month 
    span= t :this_month
  li data-end=(Date.today.beginning_of_month - 1.day) data-start=Date.today.beginning_of_month.prev_month 
    span= t :last_month
  li.custom_range data-end="" data-start="" 
    span= t :custom_range