Question

I’m trying to use time.ago using standalone ActiveSupport, required thus:

ruby
require 'active_support/core_ext/date_time/calculations'

If I try to use it as advised:

ruby
time = Chronic.parse(time_string)
time.ago

I get this error:

ArgumentError - wrong number of arguments (0 for 1):
    /home/user/.rvm/gems/ruby-1.9.2-p290/gems/activesupport-3.0.0/lib/active_support/core_ext/date_time/calculations.rb:61:in `ago'

and if I supply an argument, thus:

ruby
time.ago DateTime.now

I get this one, which I don’t understand at all:

NoMethodError - undefined method `-@' for #<DateTime:0x00000001f18168>:
    /home/passcod/.rvm/gems/ruby-1.9.2-p290/gems/activesupport-3.0.0/lib/active_support/core_ext/date_time/calculations.rb:62:in `ago'

Answer 1

The ago method is designed for you to be able to add a number of seconds (or other time units) to the current time, e.g. 10.minutes.ago.

Supplying a full date isn’t supported and doesn’t make sense as far as I can tell – what would 23rd January 2012 at 2pm.ago mean ?