title: R: ggplot2 change language of time axis
body: <p>I have the following plot:</p>
  
  <p><img src="https://i.stack.imgur.com/Ie4Jv.png" alt="enter image description here"></p>
  
  <p>and I want to change the x-axis label so that I either have "May" instead of "Mai" (preferred) or if that fails something like "14-05-21 18:00" in which the full date and the hour are given. </p>
  
  <p>The code I use for the plot is: </p>
  
  <pre><code>library(ggplot2)
  library(grid)
  ggplot(day5, aes(datetime)) + 
    geom_line(aes(y = ET.Lys, colour = "ET.Lys")) + 
    geom_line(aes(y = ET.PM, colour = "ET.PM"))+
    scale_y_continuous(breaks=c(0,0.2, 0.4, 0.6, 0.8, 1, 1.2), limits=c(0,1.2)) +
    xlab("\n date and time") +
    ylab("ET [mm/h]\n") +
    theme_bw(25)+
    theme(legend.title=element_blank(),
          legend.justification = c(1, 1), legend.position = c(1,1), 
          legend.background=element_rect(color = "grey",fill = "white", size = 0.1, linetype = "solid"),
          legend.key = element_blank(),
          legend.text=element_text(size=20))+
    geom_line(aes(y = ET.Lys, colour = "ET.Lys"),  size=1)+
    geom_line(aes(y = ET.PM, colour = "ET.PM"),  size=1)+
    theme(plot.margin=unit(c(0.5,2,0.5,0.5), "cm"))
  </code></pre>
  
  <p>and the datetime variable on the x-axis has the class </p>
  
  <pre><code>&gt; class(day5$datetime)
  [1] "POSIXct" "POSIXt" 
  </code></pre>
  
  <p>with the format</p>
  
  <pre><code>format="%Y-%m-%d %H:%M:%S", tz="Etc/GMT+0"
  </code></pre>
  
  <p>Any ideas?</p>