How to know if today's date is in a date range?

I have an event with start_time and end_time and want to check if the event is "in progress". That would be to check if today's date is in the range between the two dates.

How would you do this in a function?

In Ruby 1.9.2 === doesn't work, I get an error:

irb(main):019:0> (Time.now .. (Time.now+1)) === Time.now
TypeError: can't iterate from Time
    from (irb):19:in `each'
    from (irb):19:in `include?'
    from (irb):19:in `include?'
    from (irb):19:in `==='
    from (irb):19
    from /opt/ruby192/bin/irb:12:in `<main>'

Instead use #cover?:

irb(main):002:0> (Time.now..Time.now+4).cover?(Time.now)
=> true
irb(main):003:0> (Time.now..Time.now+4).cover?(Time.now+10)
=> false

Use ===

Actually, there is an operator that will do this. Make a Range and compare Time objects to it using the === operator.

start   = Time.now.to_i

range   = start..(start + 2)
inside  = start + 1
outside = start + 3        # ok, now...

range === inside  # true
range === outside # false

If you're using Rails you can use TimeWithZone#between?. You'd then have something like this:

> start_time = Time.zone.parse('12pm')      => Thu, 26 Jul 2012 12:00:00 EDT -04:00
> end_time = start_time + 1.hour            => Thu, 26 Jul 2012 13:00:00 EDT -04:00
> inside = Time.zone.parse('12:30pm')       => Thu, 26 Jul 2012 12:30:00 EDT -04:00
> outside = Time.zone.parse('1:30pm')       => Thu, 26 Jul 2012 13:30:00 EDT -04:00
> inside.between?(start_time, end_time)     => true
> outside.between?(start_time, end_time)    => false

Because the date class includes the Comparable module, every date object has a between? method.

require 'date'

today           = Date.today
tomorrow        = today + 1
one_month_later = today >> 1

tomorrow.between?(today, one_month_later) # => true

If you are using Rails, you could try this:

ruby-1.8.7-p299 :015 > a = DateTime.now
 => Fri, 02 Dec 2011 11:04:24 -0800 
ruby-1.8.7-p299 :016 > (a.beginning_of_day..a.end_of_day).include_with_range? a
 => true 
ruby-1.8.7-p299 :017 > (a.beginning_of_day..a.end_of_day).include_with_range? a+10.days
 => false 
ruby-1.8.7-p299 :018 > (a.beginning_of_day..a.end_of_day).include_with_range? a+25.hours
 => false 
ruby-1.8.7-p299 :019 > (a.beginning_of_day..a.end_of_day).include_with_range? a+2.hours
 => true 

Note: I just used beginning_of_day and end_of_day to provide an easy range. The important part is the include_with_range? method on a Range.