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

我遇到过这样的情况,我们有日期而不是日期时间,并且日期只能在开始/结束时重叠。示例如下:

(绿色是当前间隔,蓝色块是有效间隔,红色块是重叠间隔)。

我将Ian Nelson的答案改编为以下解决方案:

   (startB <= startA && endB > startA)
|| (startB >= startA && startB < endA)

这匹配所有重叠情况,但忽略允许的重叠情况。

其他回答

为了涵盖PHP/LaravelCarbon包中的所有重叠情况,您可以在Charles的答案中展开逻辑,如下所示。

if ( ($startTime1->between($startTime2, $endTime2, true) || $endTime1->between($startTime2, $endTime2, true)) || (($startTime1 <= $endTime2) && ($endTime2 <= $endTime1)) ){
//Complete Overlap, Partial Left Overlap, Partial Right Overlap. 
}

这将检查StartTime1是否在(StartTime2-EndTime2)范围之间,或者EndTime1是否位于(StartTime2-EndTime2的范围之间。

其余部分完全重叠,如其他答案所述。

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);
    }

如果您提供一个日期范围作为输入,并希望找出它是否与数据库中的现有日期范围重叠,则以下条件可以成功满足您的需求

假设您从表单输入中提供了@StartDate和@EndDate。

条件是:

如果@StartDate在existingStartDate之前,而在existing EndDate之后,那么我们可以说@StartDate's在现有日期范围的中间,因此我们可以断定它将重叠

@StartDate >=existing.StartDate And @StartDate <= existing.EndDate) 

如果@StartDate在现有StartDate之后,而@EndDate在现有的StartDate之前,我们可以说它将重叠

 (@StartDate <= existing.StartDate And @EndDate >= existing.StartDate)

如果@StartDate晚于现有的StartDate,而@EndDate先于现有的EndDate,我们可以得出结论,所提供的日期范围吞噬了现有的日期范围,因此重叠

 (@StartDate <= existing.StartDate And @EndDate >= existing.EndDate))

如果任何条件成立,则提供的日期范围与数据库中的现有日期范围重叠。

这里有一个可以在本地使用的通用方法。

    // Takes a list and returns all records that have overlapping time ranges.
    public static IEnumerable<T> GetOverlappedTimes<T>(IEnumerable<T> list, Func<T, bool> filter, Func<T,DateTime> start, Func<T, DateTime> end)
    {
        // Selects all records that match filter() on left side and returns all records on right side that overlap.
        var overlap = from t1 in list
                      where filter(t1)
                      from t2 in list
                      where !object.Equals(t1, t2) // Don't match the same record on right side.
                      let in1 = start(t1)
                      let out1 = end(t1)
                      let in2 = start(t2)
                      let out2 = end(t2)
                      where in1 <= out2 && out1 >= in2
                      let totover = GetMins(in1, out1, in2, out2)
                      select t2;

        return overlap;
    }

    public static void TestOverlap()
    {
        var tl1 = new TempTimeEntry() { ID = 1, Name = "Bill", In = "1/1/08 1:00pm".ToDate(), Out = "1/1/08 4:00pm".ToDate() };
        var tl2 = new TempTimeEntry() { ID = 2, Name = "John", In = "1/1/08 5:00pm".ToDate(), Out = "1/1/08 6:00pm".ToDate() };
        var tl3 = new TempTimeEntry() { ID = 3, Name = "Lisa", In = "1/1/08 7:00pm".ToDate(), Out = "1/1/08 9:00pm".ToDate() };
        var tl4 = new TempTimeEntry() { ID = 4, Name = "Joe", In = "1/1/08 3:00pm".ToDate(), Out = "1/1/08 8:00pm".ToDate() };
        var tl5 = new TempTimeEntry() { ID = 1, Name = "Bill", In = "1/1/08 8:01pm".ToDate(), Out = "1/1/08 8:00pm".ToDate() };
        var list = new List<TempTimeEntry>() { tl1, tl2, tl3, tl4, tl5 };
        var overlap = GetOverlappedTimes(list, (TempTimeEntry t1)=>t1.ID==1, (TempTimeEntry tIn) => tIn.In, (TempTimeEntry tOut) => tOut.Out);

        Console.WriteLine("\nRecords overlap:");
        foreach (var tl in overlap)
            Console.WriteLine("Name:{0} T1In:{1} T1Out:{2}", tl.Name, tl.In, tl.Out);
        Console.WriteLine("Done");

        /*  Output:
            Records overlap:
            Name:Joe T1In:1/1/2008 3:00:00 PM T1Out:1/1/2008 8:00:00 PM
            Name:Lisa T1In:1/1/2008 7:00:00 PM T1Out:1/1/2008 9:00:00 PM
            Done
         */
    }

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;