Add and subtract based on the date passed in, integer is addition, negative number is subtraction, but day.
Num can be passed in: 1,2,3,-1,-2,-3, and so on, the default is to add a day; date can be passed in: 2017-01-01 format, the default is the day date.
function datechange (num = 1,date = False) {
if (!date) {
Date = new Date ()///The current date is the default when no value is passed in
Date = Date.getfullyear () + '-' + (Date.getmonth () + 1) + '-' + date.getdate ();
}
Date + = "00:00:00";//Set to 12 o'clock in the morning today
Date = Date.parse (new date)/1000;//converted to timestamp
Date + = (86400) * num;//modified timestamp
var newdate = new Date (parseint (Date) * 1000);//Convert to TIME
return newdate.getfullyear () + '-' + (Newdate.getmonth () + 1) + '-' + newdate.getdate ();
}
Call Result:
1, Datechange ();
Results:
2, Datechange (30);
Results:
3, Datechange (-10);
Results:
4, Datechange (3, ' 2018-02-27 ');
Results:
5, Datechange (-2, ' 2016-3-1 ');
Results:
JS date plus minus (days), time plus minus, date arithmetic, can be called directly