ggplot: set a time range for facets plotting based on date
<p>I just want to look at the trend (i.e., Y) in a time series dataset from 7am to 9am everyday.</p>

<p>Do you know how to plot it in ggplot? </p>

<p>Each subfigure in the ggplot facet shows the trend Y from 7am to 9am each day (2010/1/1 to 2010/1/14).</p>

<p>Here is my dataset:</p>

<pre><code>  DateTime &lt;- seq(as.POSIXct("2010/1/1 00:00"), as.POSIXct("2010/1/15 00:00"), "min")
  Y &lt;- rnorm(n=length(DateTime), mean=100, sd=1)
  df &lt;- data.frame(DateTime, Y)
</code></pre>

<p>Thanks a lot!</p>