title: How to determine if date is a weekend or not (not using lubridate)
body: <p>I have a vector of date objects (<code>yyyy-mm-dd</code>) and I want to determine if any of them are on weekend or not. Is there a function that can determine this straightaway? </p>
  
  <p>I can use <code>wday()</code> in the <strong>lubridate</strong> package and then determine if returned value is <code>01</code> or <code>07</code>, but anything else more straightforward?</p>
  
  <pre><code>x &lt;- seq(Sys.Date()-10, Sys.Date(), by = 1)
  x[lubridate::wday(x) %in% c(1, 7)]
  </code></pre>