javascript - 日期差异应为零但是18小时

Question

This one has stumped me. It should be so simple I would think. I am doing some very simple date subtraction in Javascript. I am subtracting the same dates and I would think it would give zero hours, but it gives 18 hours.

 let inDate = new Date('Tue Aug 27 2019 00:00:00 GMT-0500 (Central Daylight Time)').getTime(); let outDate = new Date('Tue Aug 27 2019 00:00:00 GMT-0500 (Central Daylight Time)').getTime(); document.getElementById('date').innerHTML = new Date(outDate - inDate); 

 <div id='date'> </div> 

In case it produces different results based on where you are, the result I am getting is this:

Wed Dec 31 1969 18:00:00 GMT-0600 (Central Standard Time)

Answer 1

This is due to your timezone . If you convert to GMT String before print it the time will be correct. (Jan 01, 1969 00:00:00)

 new Date(outDate - inDate).toGMTString()

You should see the correct date.

 let inDate = new Date('Tue Aug 27 2019 00:00:00 GMT-0500 (Central Daylight Time)').getTime() let outDate = new Date('Tue Aug 27 2019 00:00:00 GMT-0500 (Central Daylight Time)').getTime() console.log(new Date(inDate - outDate).toGMTString())