title: Why weekdays returns the week day in German?
body: <p>I'm on Ubuntu 18.04 and doing the following returns the day of the week in German .. why?</p>
  
  <pre><code>library(lubridate)
  ts &lt;- c(1129503178, 850121164, 848329742, 1199772925, 1114229246)
  weekdays(as_datetime(ts))
  [1] "Sonntag"  "Montag"   "Montag"   "Dienstag" "Samstag" 
  </code></pre>
  
  <p>How can I change it to either English or a number for each week day?</p>
  
  <p><strong>UPDATE</strong> doing <code>sessionInfo()</code> yields the following result:</p>
  
  <pre><code>&gt; sessionInfo()
  R version 3.6.1 (2019-07-05)
  Platform: x86_64-pc-linux-gnu (64-bit)
  Running under: Ubuntu 18.04.3 LTS
  
  Matrix products: default
  BLAS:   /usr/lib/x86_64-linux-gnu/blas/libblas.so.3.7.1
  LAPACK: /usr/lib/x86_64-linux-gnu/lapack/liblapack.so.3.7.1
  
  locale:
   [1] LC_CTYPE=en_US.UTF-8       LC_NUMERIC=C               LC_TIME=de_CH.UTF-8        LC_COLLATE=en_US.UTF-8     LC_MONETARY=de_CH.UTF-8   
   [6] LC_MESSAGES=en_US.UTF-8    LC_PAPER=de_CH.UTF-8       LC_NAME=C                  LC_ADDRESS=C               LC_TELEPHONE=C            
  [11] LC_MEASUREMENT=de_CH.UTF-8 LC_IDENTIFICATION=C
  </code></pre>