两个Date（）在几个月内的JavaScript差异
这个问题在这里已经有了答案：
希望这可以帮助你
// Set the unit values in milliseconds.
var msecPerMinute = 1000 * 60;
var msecPerHour = msecPerMinute * 60;
var msecPerDay = msecPerHour * 24;
// Set a date and get the milliseconds
var date = new Date('6/15/1990');
var dateMsec = date.getTime();
// Set the date to January 1, at midnight, of the specified year.
date.setMonth(0);
date.setDate(1);
date.setHours(0, 0, 0, 0);
// Get the difference in milliseconds.
var interval = dateMsec - date.getTime();
// Calculate how many days the interval contains. Subtract that
// many days from the interval to determine the remainder.
var days = Math.floor(interval / msecPerDay );
interval = interval - (days * msecPerDay );
// Calculate the hours, minutes, and seconds.
var hours = Math.floor(interval / msecPerHour );
interval = interval - (hours * msecPerHour );
var minutes = Math.floor(interval / msecPerMinute );
interval = interval - (minutes * msecPerMinute );
var seconds = Math.floor(interval / 1000 );
// Display the result.
document.write(days + " days, " + hours + " hours, " + minutes + " minutes, " + seconds + " seconds.");
//Output: 164 days, 23 hours, 0 minutes, 0 seconds.
你会考虑一个外部图书馆吗？ 查看http://momentjs.com/
你可以轻松地做类似的事情
date1.diff(date2, 'months')