[tsigel]

var date1 = new Date('10.05.12 16:30'); 
var date2 = new Date('10.05.13 15:20'); 
var delta = date2-date1; 
var hours = Math.round(delta / (60*60*1000)); 
var minutes = (delta-hours*60*60*1000) / (60*1000); 
alert(hours + ' ' + minutes);

Так?