title: R plot() produces date labels in Russian
body: <p>I'm working on a machine with Russian Win 8.1. </p>
  
  <p>While installing RStudio I chose English as default language, but when dealing with dates (POSIXt), <code>plot()</code> gives me an output with Russian labels on the time axis.</p>
  
  <p>How can I fix it? I want English.</p>
  
  <p>Thanks in advance!</p>
  
  <p><img src="https://i.stack.imgur.com/UmNZb.png" alt="enter image description here"></p>