c# - Getting Overlapping Start and End Date -

given daterange need return list of start , enddates overlaps given period.

what best way it? time in advance.

        static void main(string[] args)           {              //period 1stmarch 20th april              var startdate = new datetime(2011, 03, 1);              var enddate = new datetime(2011, 4, 20);                list<bookedperiod> bookedperiods=new list<bookedperiod>();              bookedperiods.add(new bookedperiod {startdate = new datetime(2011, 02, 5), enddate = new datetime(2011, 3, 15)});              bookedperiods.add(new bookedperiod { startdate = new datetime(2011, 03, 20), enddate = new datetime(2011, 4, 10) });              bookedperiods.add(new bookedperiod { startdate = new datetime(2011, 04, 01), enddate = new datetime(2011, 4, 15) });               list<overlappedperiod> myoverllappedperiods = getoverllapedperiods(startdate, enddate, bookedperiods);           }            public static list<overlappedperiod>getoverllapedperiods(datetime startdate,datetime enddate,list<bookedperiod>bookedperiods)           {              list<overlappedperiod>overlappedperiods=new list<overlappedperiod>();               // given daterange need return list of start , enddates overlaps              //??how                return overlappedperiods;           }        }         public class bookedperiod        {           public datetime startdate { get; set; }           public datetime enddate { get; set; }        }          public class overlappedperiod        {           public datetime startdate { get; set; }           public datetime enddate { get; set; }        } 

edited

i have decided edit in hope of clarifing , therefore helping has me. confused overlapped vs intersect. scenario might help

i have booked subscription gym goes 01 march 11 20 april 11

i go on holiday between 05 feb 11 15 mar 11

i need start , end date when subscription valid not going gym result should startdate=1 march 2011 enddate =15 march 2011

myattempt: static void main() { //holiday period var startdate = new datetime(2011, 02, 5); var enddate = new datetime(2011, 3, 15);

             list<bookedperiod> bookedperiods = new list<bookedperiod>();              bookedperiods.add(new bookedperiod { startdate = new datetime(2011, 02, 5), enddate = new datetime(2011, 4, 20) });               list<overlappedperiod> overlappedperiods=new list<overlappedperiod>();               foreach (var bookedperiod in bookedperiods)              {                 datetime newstartdate = new datetime();                 datetime newenddate = new datetime();                 overlappedperiod overlappedperiod=new overlappedperiod();                 overlappedperiod.startdate = newstartdate;                 overlappedperiod.enddate = newenddate;                  getdaterange(bookedperiod.startdate, bookedperiod.enddate, out newstartdate, out newenddate);                 overlappedperiods.add(overlappedperiod);               }              //do            }            private static void getdaterange(datetime startdate,datetime enddate,out datetime newstartdate,out datetime newenddate)            {               /*                * need start , end date when subscription valid not going gym                    result should startdate=1 march 2011 enddate =15 march 2011                 */            } 

are looking dates within provided period, or partially?

completely within range:

var overlapped =      period in bookedperiods     period.startdate >= startdate && period.enddate <= enddate     select new overlappedperiod { startdate = period.startdate, enddate = period.enddate }; overlappedperiods = overlapped.tolist();     

partially overlapping:

var overlapped =      period in bookedperiods     (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();