在红宝石中获得两个日期之间的月数，年数

Question

我正在尝试编写 web ui 测试以根据用户输入 (watir-webdriver) 从 jquery 日历中选择日期，如何在两个给定日期之间找到月数年，我搜索了几个解决方案无法得到我想要的想要

date1 = Date::strptime("2013-09-19", "%Y-%m-%d")  
date2 = Date::strptime("2013-09-25", "%Y-%m-%d")  
date3 = Date::strptime("2013-10-01", "%Y-%m-%d")  
date4 = Date::strptime("2014-01-20", "%Y-%m-%d")  
date5 = Date::strptime("2014-12-01", "%Y-%m-%d")  

想要的输出

diff between date1,date2 -- 0 yrs, 0 month(s)  
diff between date1,date3 -- 0 yrs, 1 month(s)  
diff between date1,date4 -- 0 yrs, 4 month(s)  
diff between date1,date5 -- 1 yrs, 3 month(s)  

我还检查了 time_diff gem

Answer 1

我会计算月差（请注意，我们在这里忽略了日差），然后将该数字除以 12 来计算年数：

##
# Calculates the difference in years and month between two dates
# Returns an array [year, month]
def date_diff(date1,date2)
  month = (date2.year * 12 + date2.month) - (date1.year * 12 + date1.month)
  month.divmod(12)
end

date_diff date1, date4 #=> [0, 4]
date_diff date1, date2 #=> [0, 0]
date_diff date1, date3 #=> [0, 1]
date_diff date1, date5 #=> [1, 3]

Answer 2

这是我的尝试。在多个单元中工作：

  def date_diff(date1, date2, units=:months)
    seconds_between = (date2.to_i - date1.to_i).abs
    days_between = seconds_between / 60 / 60 / 24

    case units
      when :days
        days_between.floor
      when :months 
        (days_between / 30).floor
      when :years
        (days_between / 365).floor
      else
        seconds_between.floor
    end
  end

用法：

date_diff(Time.now, 10.years.ago - 77.days, :years)  #=> 10 
date_diff(10.years.ago - 77.days, Time.now, :months) #=> 124
date_diff(10.years.ago - 77.days, Time.now, :days)   #=> 3730

Answer 3

我从TimeDifference gem 获取了这个，但它工作得非常好，我想我会分享。如果您使用的是 Rails，请使用以下代码创建一个名为 TimeDifference 的类：

class TimeDifference
  private_class_method :new

  def self.between(start_time:, end_time:)
    new(start_time, end_time)
  end

  def in_seconds
    @time_diff
  end

  def in_minutes
    in_component(:minutes)
  end

  def in_hours
    in_component(:hours)
  end

  def in_days
    in_component(:days)
  end

  def in_weeks
    in_component(:weeks)
  end

  def in_months
    (@time_diff / (1.day * 30.42)).round(2)
  end

  def in_years
    in_component(:years)
  end

  private

  def initialize(start_time, end_time)
    start_time = time_in_seconds(start_time)
    end_time   = time_in_seconds(end_time)
    @time_diff = (end_time - start_time).abs
  end

  def time_in_seconds(time)
    time.to_time.to_f
  end

  def in_component(component)
    (@time_diff / 1.send(component)).round(2)
  end
end

然后简单地调用：

start_time = DateTime.parse('2 June, 1999 9:00:00')
end_time = DateTime.parse('19 April, 2021 9:00:00')

time_difference = TimeDifference.between(
  start_time: start_time,
  end_time: end_time
)

time_difference.in_days
=> 7992.0

time_difference.in_months
=> 262.72

time_difference.in_years
=> 21.88

注意：如果您不使用 Rails，则可能需要 ActiveSupport。