Discussion on Addition and Subtraction Time in javascript

In the morning, I encountered 1 problem when dealing with 1 date parameter in js, and I didn't know how to add or subtract time.

The original idea is to take out year, month, day, hour, minute and second by yourself, and then add them manually. . . At first, I wanted to borrow a bit directly. Later, I thought, which is so easy.

Finally, after a morning's groping, it was finally settled.

The first is how to display a standard date and time format "yyyy-mm-dd hh: MM: ss". For the time being,

var dtNow = new Date (). //Current time

The standard date and time are spelled out, and dtNow. getFullYear (), dtNow. getMonth () + 1), dtNow. getDate (), dtNow. toTimeString (). split ("", 1) [0] is the information to be contained in this standard time string.

And the way to add and subtract time is. For example, add N days to the current dtNow

var dtNew = new Date (dtNow. getTime () +N*24*60*60*1000);

Then use dtNew. getFullYear () and so on to get data such as date and time.

Also writing this time would like to overload 1 under the toString method, because the original toString returned a bit rich.. but the format is not good.