Count number of days between two dates

Question

With the Date (and DateTime) classes you can do (end_date - start_date).to_i to get the number of days difference.

Assuming that end_date and start_date are both of class ActiveSupport::TimeWithZone in Rails, then you can use:

(end_date.to_date - start_date.to_date).to_i

Rails has some built in helpers that might solve this for you. One thing to keep in mind is that this is part of the Actionview Helpers, so they wont be available directly from the console.

Try this

<% start_time =  "2012-03-02 14:46:21 +0100" %>
<% end_time   =  "2012-04-02 14:46:21 +0200" %>
<%= distance_of_time_in_words(start_time, end_time)  %>

 "about 1 month"

I kept getting results in seconds, so this worked for me:

(Time.now - self.created_at) / 86400