我想使两个日期之间的条件不同

Question

const today = new Date();
var date2 = new Date("10/29/2021");
var Difference_In_Time = date2.getTime() - today.getTime();
var Difference_In_Days = Difference_In_Time / (1000 * 3600 * 24);
document.write(
"Total number of days between dates  <br>" +
today +
"<br> and <br>" +
date2 +
" is: <br> " +
Difference_In_Days
);

Answer 1

先说明问题所在。

但是如果你只是想要一个正确的方法来获得日期差异。你应该看看下面的代码:

不要用较小的日期减去较大的日期。如果你想这样做，你必须得到它的绝对值。你应该像下面的代码那样做。

const date1 = new Date('9/20/2021');
const date2 = new Date();
const diffTimeInMilliseconds = Math.abs(date2 - date1); // this gives time difference in milliseconds
const diffDays = Math.floor(diffTimeInMilliseconds / (1000 * 60 * 60 * 24)) // 1 second = 1000 ms, 1 minute = 60 s, 1 hour = 60 m, 1 day = 24 h; 
console.log(diffTimeInMilliseconds + " milliseconds");
console.log(diffDays + " days");