javascript - Calculate difference between 2 dates considering Daylight Saving Time -

javascript - Calculate difference between 2 dates considering Daylight Saving Time -

given start date, , number of days, need display end date = start date + number of days.

so did this:

var enddate=new date(startdate.gettime()+one_day);

everything works fine, except 25 , 26 oct gives 1 day less.

ex.:

2014-01-01 + 2 days = 2014-01-03 2014-10-25 + 2 days = 2014-10-26 (here case need treat).

this difference appear because of clock going 1 hour. practically 2014-10-27 00:00:00 becomes 2014-10-26 23:00:00.

a simple solution compute @ hr (example 3 am). want display note when happens.

for example, if user inputs 2014-10-25, show popup saying [something].

now here real problem... can't seem find algorithm says when clocks goes in year x.

example... in 2014 day 26 october. in 2016 30 oct (https://www.gov.uk/when-do-the-clocks-change). why? date looks random be, don't think is. so... when clock go back/forward?

edit: answers/comments helpful related how prepare problem. but... passed stage. have itch "how on earth days when clock changed computed?".

to find difference between 2 dates in whole days, create date objects, subtract 1 other, split milliseconds in 1 day , round. remainder out 1 hr daylight saving round right value.

you may need little function convert strings dates:

// homecoming date given iso date yyyy-mm-dd function parseisodate(ds) { var d = ds.split(/\d/); homecoming new date(d[0], --d[1], d[2]); }

get difference in days:

function datediff(d0, d1) { homecoming math.round((d1 - d0)/8.64e7); } // 297 console.log(datediff(parseisodate('2014-01-01'), parseisodate('2014-10-25')));

if want add together days date, like:

// add together 2 days 2014-10-25 var d = new date(2014, 9, 25); d.setdate(d.getdate() + 2); console.log(d); // 2014-10-27

the built–in date object takes business relationship of daylight saving (thought there bugs in browsers).

javascript date clock hour