title: Scaling POSIXlt data in histogram using ggplot2
body: <p>How to change the labels at x-axis in the form "2013-07-01 00:30:00"?</p>
  
  <pre><code>library(ggplot2)
  
  a&lt;-as.POSIXlt("2013-07-01 00:30:00")
  b&lt;-as.POSIXlt("2013-07-5 00:30:00")
  aI&lt;-as.numeric(a)
  bI&lt;-as.numeric(b)
  
  times&lt;-sample(seq(aI,bI,by=2),100)
  ggplot(, aes(x=times)) + 
  geom_histogram(aes(y=..count..),binwidth=10000, colour="black") +
  theme(axis.text.x = element_text(angle=45))
  </code></pre>
  
  <p>And I looking for a function to add a curve like</p>
  
  <pre><code> geom_density(alpha=.2, fill="#FF6666")
  </code></pre>
  
  <p>but at the plot above, so that the curve fits on the ..count.. property.</p>