How to get the number of days in a given month in Ruby, accounting for year?

Question

I\'m sure there\'s a good simple elegant one-liner in Ruby to give you the number of days in a given month, accounting for year, such as \"February 1997\". What is it?

Answer 1

Time.now.end_of_month.day - for current month

Date.parse("2014-07-01").end_of_month.day - use date of first day in month.

Depends on ActiveSupport

Answer 2

For a given Date object I feel like the easiest is:

Date.today.all_month.count

Answer 3

as of rails 3.2... there's a built in version: http://api.rubyonrails.org/classes/Time.html#method-c-days_in_month

(alas, it shows up after this answer, which takes folks on a long hike)

Answer 4

Since the time is irrelevant for this purpose then you just need a date object:

[*Date.today.all_month].size

Answer 5

Use Time.days_in_month(month) where month = 1 for January, 2 for Feb, etc.

Answer 6

revise the input for other format

def days_in_a_month(date = "2012-02-01")
  date.to_date.end_of_month.day
end