How to get time stamp in same format every 10 seconds in js

Question

there is a test route in nodejs as shown below

router.get('/testdata', function (req, res) {
    var startTime="2016-11-30 23:40:00"
    var endTime = new Date("2016-11-30 23:40:00");
    endTime.setSeconds(endTime.getMinutes() + 2)
    console.log("************getDeviceData*********************")
    console.log(startTime)
    console.log(endTime);
    dataTrackerInfoDetails.timerId = setInterval(function(){
        startTime=endTime;
        var endTime = new Date(startTime);
        endTime= endTime.setSeconds(endTime.getMinutes() + 2)
        console.log("************after first*********************")
        console.log(startTime)
        console.log(endTime);

    },dataTrackerInfoDetails.timerInterval*1000);
})

Every 10 seconds i need to get the date format as shown below with 2 minutes increment from the current date

************getDeviceData*********************
2016-11-30 23:40:00
2016-11-30T18:10:42.000Z
************after before*********************
2016-11-30 23:40:00
undefined

But i will get undefined

expected output is

************getDeviceData*********************
  Start date  2016-11-30 23:40:00
    2016-11-30T18:10:42.000Z
    ************after before*********************
    2016-11-30T18:10:42.000Z
     2016-11-30T18:10:44.000Z
  ************after before*********************
    2016-11-30T18:10:44.000Z
     2016-11-30T18:10:46.000Z.......

Note the date should be same format 2016-11-30T18:10:44.000Z please let me now how to do it

Don't redefine `endTime` remove `var` from `var endTime = new Date(startTime);` — Satpal, Nov 28 '17 at 11:11
i tried that i will get the time in ms 1480529442000 i wanted the for in t 2016-11-30T18:10:44.000Z — DhanaLaxshmi, Nov 28 '17 at 11:15
Note that "2016-11-30 23:40:00" is not a valid ISO 8601 date string so is treated as an invalid date by at least one implementation in common use. See [*Why does Date.parse give incorrect results?*](https://stackoverflow.com/questions/2587345/why-does-date-parse-give-incorrect-results) — RobG, Nov 29 '17 at 04:34

score 0 · Answer 1 · answered Nov 29 '17 at 04:52

Your issue is here:

setInterval(function(){
    startTime=endTime;
    var endTime = new Date(startTime);

The declaration of endTime with var creates a local variable with a value of undefined before the function is executed. So when the line:

startTime=endTime;

is executed, startTime is set to undefined. Then:

var endTime = new Date(startTime);

will assign an invalid date to endTime. Also, where you have:

endTime = endTime.setSeconds(endTime.getMinutes() + 2)

you are mixing setSeconds with getMinutes, and the return value from setSeconds is a time value (i.e. number), not a Date, so even if you fix the other errors, you'll get an error as numbers don't have Date methods.

What you probably want to do is:

// Using an IIFE to mimic a callback
(function(){
  // Create start and end as Dates, use valid ISO 8601 format
  var startTime = new Date("2016-11-30T23:40:00");
  var endTime = new Date("2016-11-30T23:40:00");
  // Fix second/minutes mixup
  endTime.setMinutes(endTime.getMinutes() + 2);
  console.log("************getDeviceData*********************")
  console.log(startTime)
  console.log(endTime);
  
  // Just call the timer
  setInterval(function(){
    startTime = endTime;
    // Don't declare a local endTime
    endTime = new Date(startTime);
    // Modify endTime in place and fix seconds/minutes
     endTime.setMinutes(endTime.getMinutes() + 2)
     console.log("************after before*********************")
     console.log(startTime)
     console.log(endTime);
  }, 1000); // run at 1 second intervals for test
}());

You probably want to put some limit on how often this runs. Keep a reference to the value returned by setInterval and then use it to call clearInterval when some condition is met.

How to get time stamp in same format every 10 seconds in js

1 Answers1