Ruby Year-Month-Date of last Sunday

Question

I need to calculate in the format of 2014-01-20 the last two Sundays.

So, last_sunday = 2014-01-20 and most_recent_sunday = 2014-01-26 .

I am using Rails 4.0 and Ruby 2.0. How can I get these dates?

Answer 1

In rails 4:

most_recent_sunday = Time.now.sunday.to_s

last_sunday =        Time.now.last_week.sunday.to_s

To get it to the format you are after:

DateTime.parse(most_recent_sunday).strftime("%Y-%m-%d")

http://apidock.com/rails/v4.0.2/DateAndTime/Calculations/sunday http://apidock.com/rails/v4.0.2/DateAndTime/Calculations/last_week

Answer 2

I suggest you take a look at the chronic gem

require 'chronic'
Chronic.parse("last sunday")
=> 2014-01-26 12:00:00 +0200

You can also use rail's active_support to subtract 7.days from the date computed above =)

Answer 3

[11] pry(main)> last_sunday = Time.now - (Time.now.wday + 7) * 86400
=> 2014-01-19 17:17:19 -0600
[12] pry(main)> most_recent_sunday = Time.now - (Time.now.wday) * 86400
=> 2014-01-26 17:18:03 -0600

Answer 4

A pure Ruby solution:

require 'date'

last_two_weeks   = (Date.today-13)..Date.today
last_two_sundays = last_two_weeks.select &:sunday?

puts last_two_sundays #=> 2014-01-19, 2014-01-26