Calculate timespan in JavaScript

Question

I have a .net 2.0 ascx control with a start time and end time textboxes. The data is as follows:

txtStart.Text = 09/19/2008 07:00:00

txtEnd.Text = 09/19/2008 05:00:00

I would like to calculate the total time (hours and minutes) in JavaScript then display it in a textbox on the page.

Answer 1

function stringToDate(string) {
        var matches;
    if (matches = string.match(/^(\d{4,4})-(\d{2,2})-(\d{2,2}) (\d{2,2}):(\d{2,2}):(\d{2,2})$/)) {
       return new Date(matches[1], matches[2] - 1, matches[3], matches[4], matches[5], matches[6]);
    } else {
       return null;
    };
}

    function getTimeSpan(ticks) {
        var d = new Date(ticks);
        return {
            hour: d.getUTCHours(), 
            minute: d.getMinutes(), 
            second: d.getSeconds()
        }
    }

    var beginDate = stringToDate('2008-09-19 07:14:00');
    var endDate = stringToDate('2008-09-19 17:35:00');

    var sp = getTimeSpan(endDate - beginDate);
    alert("timeuse：" + sp.hour + " hour " + sp.minute + " minute " + sp.second + " second ");

you can use getUTCHours() instead Math.floor(n / 3600000);

Answer 2

Once your textbox date formats are known in advance, you can use Matt Kruse's Date functions in Javascript to convert the two to a timestamp, subtract and then write to the resulting text box.

Equally the JQuery Date Input code for stringToDate could be adapted for your purposes - the below takes a string in the format "YYYY-MM-DD" and converts it to a date object. The timestamp (getTime()) of these objects could be used for your calculations.

stringToDate: function(string) {
    var matches;
    if (matches = string.match(/^(\d{4,4})-(\d{2,2})-(\d{2,2})$/)) {
       return new Date(matches[1], matches[2] - 1, matches[3]);
    } else {
       return null;
    };
}