title: Finding the date of a data point in a R time-series
body: <p>I make a time series:</p>
  
  <blockquote>
    <p>t = ts(rnorm(12*50), start=1900, freq=12)  </p>
  </blockquote>
  
  <p>and then find the maximum with <code>max(t)</code>. Is there any convenient way to find out what date this maximum occurred at?</p>