csexton/app.rb

## app.rb
require 'sinatra'
require 'sinatra/ratpack'
require 'coffee-script'

helpers do
  def localtime_tag(time)
    time = Time.parse(time) unless time.respond_to? :strftime
    formatted_str = time.strftime('%Y-%m-%dT%H:%M:%S%z')
    content_tag :span, formatted_str, class: 'localtime'
  end
end

get '/' do
    erb :index
end
get '/localtime.js' do
    coffee :localtime
end

## views-index.erb
<!DOCTYPE html>
<html lang="en">
  <head>
    <title>Sinatra - Localtime</title>
  </head>
  <body>
    <h1>What time is it here?</h1>
    <ul>
      <li> "2012-10-10 06:42:47 UTC" =&gt; <%= localtime_tag "2012-10-10 06:42:47 UTC" %>
      <li><%= localtime_tag "2012-10-10 06:42:47 UTC" %>
      <li><%= localtime_tag Time.now %>
      <li><%= localtime_tag Time.now.utc %>
    </ul>


    <!-- Include JS -->
    <script src="https://ajax.googleapis.com/ajax/libs/jquery/1.5.0/jquery.min.js"></script>
    <script src="/localtime.js" type="text/javascript"></script>
    <script type="text/javascript">
      $(document).ready(function() {
        return $(".localtime").localtime_from_utc();
      });
    </script>
  </body>
</html>

## views-localtime.coffee
#
# To parse the date the input text should include the zimezone so when the
# browser parses the string it will be converted to the local time
#
# In ruby we can use the following:
#    date.strftime('%Y-%m-%dT%H:%M:%S%z')
#

(($) ->
  $.fn.localtime_from_utc = ->
    @each ->
      # get provided date
      tagText = $(this).html()
      d = new Date(tagText)

      # format the date
      hour = d.getHours()
      if hour < 12
        meridiem = "AM"
      else
        meridiem = "PM"
      hour = 12  if hour is 0
      hour = hour - 12  if hour > 12
      local_date_string = hour +
        ":" +
        d.getMinutes() +
        " " +
        meridiem +
        " " +
        (d.getMonth()+1)+ # Months are zero index
        "/" +
        d.getDate() +
        "/" +
        d.getFullYear()
      $(this).html local_date_string
      $(this).attr "title", tagText

) jQuery
	require 'sinatra'
	require 'sinatra/ratpack'
	require 'coffee-script'

	helpers do
	def localtime_tag(time)
	time = Time.parse(time) unless time.respond_to? :strftime
	formatted_str = time.strftime('%Y-%m-%dT%H:%M:%S%z')
	content_tag :span, formatted_str, class: 'localtime'
	end
	end

	get '/' do
	erb :index
	end
	get '/localtime.js' do
	coffee :localtime
	end
	<!DOCTYPE html>
	<html lang="en">
	<head>
	<title>Sinatra - Localtime</title>
	</head>
	<body>
	<h1>What time is it here?</h1>
	<ul>
	<li> "2012-10-10 06:42:47 UTC" => <%= localtime_tag "2012-10-10 06:42:47 UTC" %>
	<li><%= localtime_tag "2012-10-10 06:42:47 UTC" %>
	<li><%= localtime_tag Time.now %>
	<li><%= localtime_tag Time.now.utc %>
	</ul>



	<!-- Include JS -->
	<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.5.0/jquery.min.js"></script>
	<script src="/localtime.js" type="text/javascript"></script>
	<script type="text/javascript">
	$(document).ready(function() {
	return $(".localtime").localtime_from_utc();
	});
	</script>
	</body>
	</html>
	#
	# To parse the date the input text should include the zimezone so when the
	# browser parses the string it will be converted to the local time
	#
	# In ruby we can use the following:
	# date.strftime('%Y-%m-%dT%H:%M:%S%z')
	#

	(($) ->
	$.fn.localtime_from_utc = ->
	@each ->
	# get provided date
	tagText = $(this).html()
	d = new Date(tagText)

	# format the date
	hour = d.getHours()
	if hour < 12
	meridiem = "AM"
	else
	meridiem = "PM"
	hour = 12 if hour is 0
	hour = hour - 12 if hour > 12
	local_date_string = hour +
	":" +
	d.getMinutes() +
	" " +
	meridiem +
	" " +
	(d.getMonth()+1)+ # Months are zero index
	"/" +
	d.getDate() +
	"/" +
	d.getFullYear()
	$(this).html local_date_string
	$(this).attr "title", tagText

	) jQuery