给定开始和结束日期，我如何循环直到达到结束日期？

Question

我有一个start_dt和一个end_dt对象，类型为datetime。

我如何从start_dt循环，每次递增1天，直到我到达结束日期？

Answer 1

您可以在upto和downto个对象上使用Date和DateTime方法：

start_dt = DateTime.parse('2018-01-01')
end_dt = DateTime.parse('2018-01-15')

start_dt.upto(end_dt) { |date| puts date }
2018-01-01T00:00:00+00:00
2018-01-02T00:00:00+00:00
2018-01-03T00:00:00+00:00
2018-01-04T00:00:00+00:00
2018-01-05T00:00:00+00:00
2018-01-06T00:00:00+00:00
2018-01-07T00:00:00+00:00
2018-01-08T00:00:00+00:00
2018-01-09T00:00:00+00:00
2018-01-10T00:00:00+00:00
2018-01-11T00:00:00+00:00
2018-01-12T00:00:00+00:00
2018-01-13T00:00:00+00:00
2018-01-14T00:00:00+00:00
2018-01-15T00:00:00+00:00


end_dt.downto(start_dt) { |date| puts date }
2018-01-15T00:00:00+00:00
2018-01-14T00:00:00+00:00
2018-01-13T00:00:00+00:00
2018-01-12T00:00:00+00:00
2018-01-11T00:00:00+00:00
2018-01-10T00:00:00+00:00
2018-01-09T00:00:00+00:00
2018-01-08T00:00:00+00:00
2018-01-07T00:00:00+00:00
2018-01-06T00:00:00+00:00
2018-01-05T00:00:00+00:00
2018-01-04T00:00:00+00:00
2018-01-03T00:00:00+00:00
2018-01-02T00:00:00+00:00
2018-01-01T00:00:00+00:00

Answer 2

这个怎么样？

current_date = object.start_dt
end_date = object.end_dt

loop do
  ## do something

  ## (`:beginning_of_day` and `:end_of_day` may help you)
  current_date += 1.day
  break if current_date > end_date
end

Answer 3

尝试以下

start_date = Time.now - 30.day
=> 2017-12-16 09:19:51 +gmt
end_date = Time.now
=> 2018-01-15 09:19:44 +gmt

start_date = Date.parse "#{start_date}"
end_date = Date.parse "#{end_date}"

date_count = (end_date - start_date).to_i
=> 30

<% (1..date_count).each do |i| %>
  #Code to display using <%= i %> that you want to display    
<% end %>

希望能提供帮助

Answer 4

试试这些：

(DateTime.parse('2018-01-01')..DateTime.parse('2018-01-15')).each do |date|

  puts date

end