The generic solution would be to write a query with two conditions that checks for an interval:
//first second of the current day
var intervalStart = new Date(new Date(date - date % (24 * 60 * 60 * 1000)));
//last second of the current day
var intervalEnd = new Date(intevalStart .valueOf() + 24 * 60 * 60 * 1000);
exDB.Expenses
.filter( function(exp) {
return exp.Date >= this.minDate && exp.Date <= this.maxDate
}, {minDate: intervalStart , maxDate: intervalEnd })
.foreach(function(){...});