给定两个日期范围,确定两个日期是否重叠的最简单或最有效的方法是什么?

例如,假设我们有由DateTime变量StartDate1到EndDate1和StartDate2到EndDate2表示的范围。


当前回答

对于ruby,我也发现了这一点:

class Interval < ActiveRecord::Base

  validates_presence_of :start_date, :end_date

  # Check if a given interval overlaps this interval    
  def overlaps?(other)
    (start_date - other.end_date) * (other.start_date - end_date) >= 0
  end

  # Return a scope for all interval overlapping the given interval, including the given interval itself
  named_scope :overlapping, lambda { |interval| {
    :conditions => ["id <> ? AND (DATEDIFF(start_date, ?) * DATEDIFF(?, end_date)) >= 0", interval.id, interval.end_date, interval.start_date]
  }}

end

在这里找到它,解释很好->http://makandracards.com/makandra/984-test-if-two-date-ranges-overlap-in-ruby-or-rails

其他回答

这是我使用moment.js的javascript解决方案:

// Current row dates
var dateStart = moment("2014-08-01", "YYYY-MM-DD");
var dateEnd = moment("2014-08-30", "YYYY-MM-DD");

// Check with dates above
var rangeUsedStart = moment("2014-08-02", "YYYY-MM-DD");
var rangeUsedEnd = moment("2014-08-015", "YYYY-MM-DD");

// Range covers other ?
if((dateStart <= rangeUsedStart) && (rangeUsedEnd <= dateEnd)) {
    return false;
}
// Range intersects with other start ?
if((dateStart <= rangeUsedStart) && (rangeUsedStart <= dateEnd)) {
    return false;
}
// Range intersects with other end ?
if((dateStart <= rangeUsedEnd) && (rangeUsedEnd <= dateEnd)) {
    return false;
}

// All good
return true;

本文《.NET时间段库》通过枚举PeriodRelation描述了两个时间段之间的关系:

// ------------------------------------------------------------------------
public enum PeriodRelation
{
    After,
    StartTouching,
    StartInside,
    InsideStartTouching,
    EnclosingStartTouching,
    Enclosing,
    EnclosingEndTouching,
    ExactMatch,
    Inside,
    InsideEndTouching,
    EndInside,
    EndTouching,
    Before,
} // enum PeriodRelation

在Microsoft SQL SERVER中-SQL函数

CREATE FUNCTION IsOverlapDates 
(
    @startDate1 as datetime,
    @endDate1 as datetime,
    @startDate2 as datetime,
    @endDate2 as datetime
)
RETURNS int
AS
BEGIN
DECLARE @Overlap as int
SET @Overlap = (SELECT CASE WHEN  (
        (@startDate1 BETWEEN @startDate2 AND @endDate2) -- caters for inner and end date outer
        OR
        (@endDate1 BETWEEN @startDate2 AND @endDate2) -- caters for inner and start date outer
        OR
        (@startDate2 BETWEEN @startDate1 AND @endDate1) -- only one needed for outer range where dates are inside.
        ) THEN 1 ELSE 0 END
    )
    RETURN @Overlap

END
GO

--Execution of the above code
DECLARE @startDate1 as datetime
DECLARE @endDate1 as datetime
DECLARE @startDate2 as datetime
DECLARE @endDate2 as datetime
DECLARE @Overlap as int
SET @startDate1 = '2014-06-01 01:00:00' 
SET @endDate1 =   '2014-06-01 02:00:00'
SET @startDate2 = '2014-06-01 01:00:00' 
SET @endDate2 =   '2014-06-01 01:30:00'

SET @Overlap = [dbo].[IsOverlapDates]  (@startDate1, @endDate1, @startDate2, @endDate2)

SELECT Overlap = @Overlap

我认为,在以下情况下,两个范围重叠就足够了:

(StartDate1 <= EndDate2) and (StartDate2 <= EndDate1)

我会的

StartDate1.IsBetween(StartDate2, EndDate2) || EndDate1.IsBetween(StartDate2, EndDate2)

IsBetween是这样的

    public static bool IsBetween(this DateTime value, DateTime left, DateTime right) {
        return (value > left && value < right) || (value < left && value > right);
    }