title: extract weekdays from a set of dates in R
body: <p>I know using the <code>lubridate</code> package, I can generate the respective weekday for each date of entry. I am now dealing with a large dataset having a lot of date entries and I wish to extract weekdays for each date entries. I think it is quite impossible to search for each date and to find weekdays. I will love to have a function that will allow me to insert my date column from my data frame and will produce days corresponding to each dates of the frame.</p>
  
  <p>my frame is like</p>
  
  <pre><code>uinq_id Product_ID Date_of_order count
  1 Aarkios04_2014-09-09  Aarkios04    2014-09-09    10
  2    ABEE01_2014-08-18     ABEE01    2014-08-18     1
  3    ABEE01_2014-08-19     ABEE01    2014-08-19     0
  4    ABEE01_2014-08-20     ABEE01    2014-08-20     0
  5    ABEE01_2014-08-21     ABEE01    2014-08-21     0
  6    ABEE01_2014-08-22     ABEE01    2014-08-22     0
  </code></pre>
  
  <p>i am trying to generate</p>
  
  <pre><code>uinq_id Product_ID Date_of_order count                      weekday   
  1 Aarkios04_2014-09-09  Aarkios04    2014-09-09    10       Tues
  2    ABEE01_2014-08-18     ABEE01    2014-08-18     1       Mon  
  3    ABEE01_2014-08-19     ABEE01    2014-08-19     0       Tues   
  4    ABEE01_2014-08-20     ABEE01    2014-08-20     0       Wed 
  5    ABEE01_2014-08-21     ABEE01    2014-08-21     0       Thurs
  6    ABEE01_2014-08-22     ABEE01    2014-08-22     0       Fri
  </code></pre>
  
  <p>any help will be highly beneficial.
  thank you.</p>