【JS】求两时间差

var startTime=new Date();

.......

var now=new Date();

var diff=(now-startTime)/1000;

var d=parseInt(diff/86400);

var h=parseInt(diff/3600)-24*d;

var m=parseInt((diff % 3600) / 60);

var s=parseInt(diff % 60);

var elapsed=d+"day "+h+"hour "+m+"minute "+s+"second";