title: Finding Days Since Date in R from csv file
body: <p>I'm working with a factor of dates (dateframe$LastDate) brought in from the csv file and would like to calculate the days from today. Missing values are the norm with dates populating about 20% of 1000 rows.  </p>
  
  <p>Here's what I have so far which is returning me the factor of days since 1970.  It just feels like a lot of work to do a simple thing so I'm sure I'm off somewhere.</p>
  
  <pre><code>NumberOfDays &lt;- ifelse(!is.na(LastDate), Sys.Date()-LastDate, as.numeric(""))
  </code></pre>