Mike Sokolov thinks this is interesting: When possible, it’s a good idea to store date and time values as date objects, not as strings or numbers. From Other Objects from R in a Nutshell, 2nd Edition by Joseph Adler Publisher: O'Reilly Media, Inc. Released: October 2012 Note words to live by Share this highlight http://www.safaribooksonline.com/a/r-in-a/14/ Twitter Facebook Google Plus Email Get Instant Access Now Start a Free Trial Learn about Safari for Business Have an account? Sign in. Minimise Unlock the rest of R in a Nutshell, 2nd Edition and 30,000 other books and videos By clicking this box, you confirm that you have read and agree to the terms and conditions of our Membership Agreement, and you understand that when your trial period ends, you will be required to provide billing information if you wish to continue using the service. Unlock the rest of this book Start a Free 10-Day Trial loading Learn about Safari for Business Have an account? Sign in.