Function used to calculate the difference between two dates in human readable format

timeDelta.js

/**!
 * @preserve timeDelta
 * Copyright 2011 THEtheChad Elliott
 * Released under the MIT and GPL licenses.
 */
function timeDelta( start, end, params, only_totals ) {

    var delta = {}
      , measurements = {
            w: 604800000,
            d: 86400000,
            h: 3600000,
            m: 60000,
            s: 1000
            }
      , flags = params || 'wdhms'
    ;//var

    delta.ttl = delta.ms = Math.abs( end.getTime() - start.getTime() );

    // do caclulations for each flag
    for( i = 0; i < flags.length; i++ ) {
        delta[ flags[i] ] = delta.ms / measurements[ flags[i] ];
        // unless totals are specified,
        // value is broken down into components
        if( !only_totals ) {
            delta[ flags[i] ] = Math.floor( delta[ flags[i] ] );
            delta.ms -= delta[ flags[i] ] * measurements[ flags[i] ];
        }
    };
    
    return delta;
}