用Javascript过滤日期

Question

I am trying to filter an array which contain date(converted from string) which is greater than a particular date..

_this.downloadData.forEach(_d => _d.LogTime = _d.LogTime.toString());

console.log(_this.downloadData.filter(x=>new Date(x.LogTime) > new Date('3/11/2019 7:29:12 AM')));

But filter always return zero items

.

Array looks like below:

[0 … 99]
0:
CPUStat:""
Connectivity:""
DiskStatus:""
HostName:"HOSTname"
LastRebootStatus:null
LogTime:"Mon Mar 11 2019 07:39:12 GMT+0530 (India Standard Time)"

__proto__:
Object

Answer 1

Most of your problem here consist of the date time format not being ISO 8601 compliant. Because of this you need to clean up the date. LogTime.substring(4,23) + obj.LogTime.substring(28,33) will get the important parts from your string. Then you can use moment.js ( https://momentjs.com ), which is a must for handling time in JavaScript.

You can run the code below and see that it works

 // Your example time array let timeArray = [ { LogTime:"Mon Mar 11 2019 07:39:12 GMT+0530 (India Standard Time)" }, { LogTime:"Mon Mar 11 2019 08:39:12 GMT+0530 (India Standard Time)" }, { LogTime:"Mon Mar 11 2019 09:39:12 GMT+0530 (India Standard Time)" }, { LogTime:"Mon Mar 11 2019 10:39:12 GMT+0530 (India Standard Time)" } ], format = "MMM MM YYYY HH:mm:ssZ", shouldBeAfter = moment('Mar 11 2019 09:00:12+0530', format), result, filterDateGreaterThan = function (obj){ let sDate, mDate; sDate = obj.LogTime.substring(4,23) + obj.LogTime.substring(28,33); mDate = moment(sDate, format); // console.log(mDate); return mDate.isAfter(shouldBeAfter); }; result = timeArray.filter(filterDateGreaterThan); console.log(result); 

 <script src="https://momentjs.com/downloads/moment.min.js"></script> 

Code when not using Moment.js

 // Your example time array let timeArray = [ { LogTime:"Mon Mar 11 2019 07:39:12 GMT+0530 (India Standard Time)" }, { LogTime:"Mon Mar 11 2019 08:39:12 GMT+0530 (India Standard Time)" }, { LogTime:"Mon Mar 11 2019 09:39:12 GMT+0530 (India Standard Time)" }, { LogTime:"Mon Mar 11 2019 10:39:12 GMT+0530 (India Standard Time)" } ], shouldBeAfter = new Date('Mar 11 2019 09:00:12+0530'), result, filterDateGreaterThan = function (obj){ let sDate, date; sDate = obj.LogTime.substring(4,23) + obj.LogTime.substring(28,33); date = new Date(sDate); return date.valueOf() > shouldBeAfter.valueOf(); }; result = timeArray.filter(filterDateGreaterThan); console.log(result); 

Answer 2

You should be able to fix your problem by adding a timezone to your input. If you don't provide a timezone, your browser will use your local timezone. For instance, my timezone is PDT, so I end up seeing this:

Without Timezone in input:
input  : 3/11/2019 7:29:12 AM
output : Mon Mar 11 2019 07:29:12 GMT-0700 (Pacific Daylight Time)

With Timezone in input:
input  : Mon Mar 11 2019 07:39:12 GMT+0530 (India Standard Time)
output : Sun Mar 10 2019 19:09:12 GMT-0700 (Pacific Daylight Time)

Note that with the timezone in your input, the unix timestamp matches the output.

---

I personally use Moment Timezone to handle these cases.

Without Timezone in input:
input  : moment.tz("3/11/2019 7:29:12 AM", "Asia/Calcutta").toDate();
output : Mon Mar 11 2019 00:29:12 GMT-0700 (Pacific Daylight Time)

With Timezone in input:
input  : moment.tz("Mon Mar 11 2019 07:39:12 GMT+0530 (India Standard Time)", "Asia/Calcutta").toDate();
output : Mon Mar 11 2019 00:39:12 GMT-0700 (Pacific Daylight Time)