title: Display the x-axis on ggplot as month only in R
body: <p>I have a very simple question here. I have a dataset from 2009-2012. I want to plot the data with facets. I have created the faceted plot as follows.</p>
  
  <p>R-code</p>
  
  <pre><code>ggplot(al02428400,aes(x=date,y=as.numeric(Discharge)))+geom_line()+ylab("Discharge(cfs)")+facet_wrap(~Year,scales=("free_x"))+theme_bw()
  </code></pre>
  
  <p>The output of the above R code is as follows:</p>
  
  <p><img src="https://i.stack.imgur.com/3StEY.png" alt="enter image description here"></p>
  
  <p>On the X-axis I only want to show the month. By default it is showing month and year. Is there any way I can get rid of year ? </p>
  
  <p><strong>The fully reproducible code is as follows:</strong></p>
  
  <pre><code>library(ggplot2)
  
  url &lt;- "http://nwis.waterdata.usgs.gov/usa/nwis/uv/?cb_00060=on&amp;cb_00065=on&amp;format=rdb&amp;period=&amp;begin_date=2009-01-01&amp;end_date=2012-12-31&amp;site_no=02428400"
  download.file(url,destfile="Data load for stations/data/alabamariver-at-monroeville-2009.txt")
  
  al02428400 &lt;- read.table("Data load for stations/data/alabamariver-at-monroeville-2009.txt",header=T,skip=1,sep="\t")
  head(al02428400)
  
  sapply(al02428400,class)
  al02428400 &lt;- al02428400[-1,]
  
  names(al02428400)&lt;- c("Agency","SiteNo","Datetime", "TZ","Discharge","Status","Gageheight","gstatus")
  al02428400$date &lt;- strptime(al02428400$Datetime, format="%Y-%m-%d %H:%M")
  
  al02428400$Discharge &lt;- as.numeric(as.character(al02428400$Discharge))
  al02428400$Year &lt;- as.numeric(format(al02428400$date, "%Y"))
  ggplot(al02428400,aes(x=date,y=as.numeric(Discharge)))+geom_line()+ylab("Discharge(cfs)")+facet_wrap(~Year,scales=("free_x"))+theme_bw()
  </code></pre>
  
  <p>Thanks. </p>