Getting Overlapping Start and End Date

Question

Given a DateRange I need to return a list of Start and EndDates that overlaps the given period.

what is the best way to do it? Thanks for your time in advance.

Answer 1

One method would be to make use of the Rectangle class to calculate intersects. So the procedure would be to create a rectangle for each date range then use the Rectangle.Intersect( ) method.

Answer 2

Are you looking for dates that are completely within the provided period, or only partially?

Completely within the range:

var overlapped = 
    from period in bookedPeriods
    where period.StartDate >= startDate && period.EndDate <= endDate
    select new OverlappedPeriod { StartDate = period.StartDate, EndDate = period.EndDate };
overlappedPeriods = overlapped.ToList();    

Partially overlapping:

var overlapped = 
    from period in bookedPeriods
    where (period.StartDate >= startDate && period.EndDate <= endDate)
        || (period.EndDate >= startDate && period.EndDate <= endDate)
        || (period.StartDate <= startDate && period.EndDate >= startDate)
        || (period.StartDate <= startDate && period.EndDate >= endDate)
    select new OverlappedPeriod 
    {
        StartDate = new DateTime(Math.Max(period.StartDate.Ticks, startDate.Ticks)),
        EndDate = new DateTime(Math.Min(period.EndDate.Ticks, endDate.Ticks))
    };

overlappedPeriods = overlapped.ToList();    

Answer 3

Something like this (not tested sorry):

return bookedPeriods.Where(
    b => (b.StartDate > startDate && b.StartDate < endDate) ||
     (b.EndDate> startDate && b.EndDate < endDate) ||
     (b.StartDate < startDate && b.EndDate > endDate)
).ToList()

Answer 4

this piece of LINQ might help:

var overlappedPeriods = bookedPeriods.Where(p=>p.EndDate > startDate && p.StartDate < endDate);

then transform the results accordingly to your OverlappedPeriod class