Compute elapsed time [duplicate]

Answer 1

<script type="text/javascript">
<!-- Gracefully hide from old browsers

// Javascript to compute elapsed time between "Start" and "Finish" button clicks
function timestamp_class(this_current_time, this_start_time, this_end_time, this_time_difference) { 
        this.this_current_time = this_current_time;
        this.this_start_time = this_start_time;
        this.this_end_time = this_end_time;
        this.this_time_difference = this_time_difference;
        this.GetCurrentTime = GetCurrentTime;
        this.StartTiming = StartTiming;
        this.EndTiming = EndTiming;
    }

    //Get current time from date timestamp
    function GetCurrentTime() {
    var my_current_timestamp;
        my_current_timestamp = new Date();      //stamp current date & time
        return my_current_timestamp.getTime();
        }

    //Stamp current time as start time and reset display textbox
    function StartTiming() {
        this.this_start_time = GetCurrentTime();    //stamp current time
        document.TimeDisplayForm.TimeDisplayBox.value = 0;  //init textbox display to zero
        }

    //Stamp current time as stop time, compute elapsed time difference and display in textbox
    function EndTiming() {
        this.this_end_time = GetCurrentTime();      //stamp current time
        this.this_time_difference = (this.this_end_time - this.this_start_time) / 1000; //compute elapsed time
        document.TimeDisplayForm.TimeDisplayBox.value = this.this_time_difference;  //set elapsed time in display box
        }

var time_object = new timestamp_class(0, 0, 0, 0);  //create new time object and initialize it

//-->
</script>

    <form>
        <input type="button" value="Start" onClick="time_object.StartTiming()"; name="StartButton">
    </form>
    <form>
        <input type="button" value="Finish" onClick="time_object.EndTiming()"; name="EndButton">
    </form>
    <form name="TimeDisplayForm">
    Elapsed time:
      <input type="text" name="TimeDisplayBox" size="6">
    seconds
    </form>

Answer 2

Try something like this (FIDDLE)

// record start time
var startTime = new Date();

...

// later record end time
var endTime = new Date();

// time difference in ms
var timeDiff = endTime - startTime;

// strip the ms
timeDiff /= 1000;

// get seconds (Original had 'round' which incorrectly counts 0:28, 0:29, 1:30 ... 1:59, 1:0)
var seconds = Math.round(timeDiff % 60);

// remove seconds from the date
timeDiff = Math.floor(timeDiff / 60);

// get minutes
var minutes = Math.round(timeDiff % 60);

// remove minutes from the date
timeDiff = Math.floor(timeDiff / 60);

// get hours
var hours = Math.round(timeDiff % 24);

// remove hours from the date
timeDiff = Math.floor(timeDiff / 24);

// the rest of timeDiff is number of days
var days = timeDiff ;

Answer 3

var StopWatch = function (performance) {
    this.startTime = 0;
    this.stopTime = 0;
    this.running = false;
    this.performance = performance === false ? false : !!window.performance;
};

StopWatch.prototype.currentTime = function () {
    return this.performance ? window.performance.now() : new Date().getTime();
};

StopWatch.prototype.start = function () {
    this.startTime = this.currentTime();
    this.running = true;
};

StopWatch.prototype.stop = function () {
    this.stopTime = this.currentTime();
    this.running = false;
};

StopWatch.prototype.getElapsedMilliseconds = function () {
    if (this.running) {
        this.stopTime = this.currentTime();
    }

    return this.stopTime - this.startTime;
};

StopWatch.prototype.getElapsedSeconds = function () {
    return this.getElapsedMilliseconds() / 1000;
};

StopWatch.prototype.printElapsed = function (name) {
    var currentName = name || 'Elapsed:';

    console.log(currentName, '[' + this.getElapsedMilliseconds() + 'ms]', '[' + this.getElapsedSeconds() + 's]');
};

Benchmark

var stopwatch = new StopWatch();
stopwatch.start();

for (var index = 0; index < 100; index++) {
    stopwatch.printElapsed('Instance[' + index + ']');
}

stopwatch.stop();

stopwatch.printElapsed();

Output

Instance[0] [0ms] [0s]
Instance[1] [2.999999967869371ms] [0.002999999967869371s]
Instance[2] [2.999999967869371ms] [0.002999999967869371s]
/* ... */
Instance[99] [10.999999998603016ms] [0.010999999998603016s]
Elapsed: [10.999999998603016ms] [0.010999999998603016s]

performance.now() is optional - just pass false into StopWatch constructor function.