title: Use of DataStructure for this scenario
body: <p>I am having data in the following form -</p>
  
  <pre><code>01/04/2011  - {00:00,1.0} ; {01:00,2.0} ; {02:00,1.5} ;{04:00,2.3} 
  02/04/2011  - {00:00,2.0} ; {01:00,2.1} ; {02:00,1.5} ;{04:00,2.3}
  03/04/2011  - {00:00,3.0} ; {01:00,2.0} ; {02:00,1.6} ;{04:00,2.3}
  04/04/2011  - {00:00,1.0} ; {01:00,2.5} ; {02:00,1.57} ;{04:00,2.3}
  05/04/2011  - {00:00,1.9} ; {01:00,2.7} ; {02:00,1.5} ;{04:00,2.3}
  06/04/2011  - {00:00,1.08} ; {01:00,2.02} ; {02:00,1.9} ;{04:00,2.3}
  07/04/2011  - {00:00,1.7} ; {01:00,2.0} ; {02:00,1.10} ;{04:00,2.3}
  </code></pre>
  
  <p>I have to store them in some DataStructure so that i can access them using the dates as the key.Also for the particular day the {k,v} pairs should be ordered in the way they get inserted.</p>
  
  <p>Pls suggest which is the best DataStructure to use in this scenario with the reason why it should be used. Thanks in advance!</p>