title: Ggplot geom_segment time x-axis
body: <p>I have two questions about my <code>Gantt-chart</code> I'm plotting via <code>Ggplot2</code>'s <code>geom_segment</code> function:</p>
  <p>First of all, the time-axis is scaled based on the data points, which means sometimes one step counts for <code>1:15</code> hours and the other for like 15 minutes. How do I get a constant <code>00:00</code> - <code>24:00</code> scaled timeline?</p>
  <p>Second, when a task starts at <code>23:50</code> and its has a duration of 30 minutes, which makes the ending time <code>00:20</code>, it is plotted from <code>00:20</code> - <code>23:50</code> (almost a whole day) instead of <code>23:50</code> till the end of the x-axis (which should be <code>24:00</code>). Because the data then reaches the next day and I'm plotting for only one day, the time after <code>24:00</code> is not required to be plotted.</p>
  <p>This is the code I'm using now:</p>
  <pre><code>ggplot(GanttArrNBStairs1208) + 
      geom_segment(aes(x=Arr_GSE_Start, xend = Arr_GSE_End, 
                       y=`Arrival Trip Number`, yend=`Arrival Trip Number`, 
                       colour=LDA_Pier_Final), 
                   size = 1) + 
      theme(axis.text.x = element_text(angle = 90, hjust = 1))    
  </code></pre>
  <p>Here is a picture of my chart:
  <img src="https://i.stack.imgur.com/AOWze.png" alt="Gantt Chart via geom_segment" /></p>