ios - Split NSDate that stretches over several days into several spans -

i have 2 nsdates define span, 1 set them this

spana: 12:00 today spanb: 12:00 tomorrow 

this equals 24 hours, need create 2 ranges instead of one, no spans stretch across midnight. outcome of example above this:

spana: 12:00 today spanb: 23:59 today  spanc: 00:01 tomorrow spand: 12:00 tomorrow 

i'm not sure how this. came idea use function this:

- (nsinteger)daysbetweendate:(nsdate *)fromdatetime anddate:(nsdate *)todatetime { nsdate *fromdate; nsdate *todate;  nscalendar *calendar = [nscalendar currentcalendar];  [calendar rangeofunit:nscalendarunitday startdate:&fromdate              interval:null fordate:fromdatetime]; [calendar rangeofunit:nscalendarunitday startdate:&todate              interval:null fordate:todatetime];  nsdatecomponents *difference = [calendar components:nscalendarunitday                                            fromdate:fromdate todate:todate options:0];  return [difference day]; } 

which returns how many days span stretches across, or in other words: number of spans required. instance for-loop number of days , add logic create necessary spans.

i'm using structure spans:

typedef struct { nstimeinterval start; nstimeinterval end; } span; 

what best approach this?

since spans except possibly first , last 1 identical day-long spans, can use algorithm:

• check if initial time midnight. if not midnight, add opening span start midnight of same day
• for each day after first midnight add day-long range midnight of next day
• check if last time midnight. if not midnight, add closing span result.