A lightweight alternative to the Date object when only dealing with time in hours and minutes

TimeInMinutes.js

var TimeInMinutes = function(hours, minutes) {
    return this.init(hours, minutes);
};
TimeInMinutes.prototype = {
    hours: 0,
    minutes: 0,
    days: 0,
    time: 0,
    init: function(hours, minutes) {
        if (hours) this.hours = hours;
        if (minutes) this.minutes = minutes;
        this.refresh(true);
        return this;
    },
    refresh: function(refreshTime) {
        var normalised = this.normaliseTime(this.time);
        if (refreshTime) {
            this.time = (this.days * 24 * 60) + (this.hours * 60) + this.minutes;
        }
        this.hours = parseInt(normalised / 60);
        this.minutes = normalised % 60;
        this.updateDays();
    },
    updateDays: function() {
        this.days = parseInt(this.time / 1440);
        if (this.time < 0) {
            this.days -= 1;
        }
    },
    resetDays: function() {
        this.setDays(0);
    },
    normaliseTime: function(time) {
        if (time < 0) {
            time += 1440;
            time = this.normaliseTime(time);
        }
        return time;
    },
    setHours: function(hours) {
        this.hours = hours;
        this.refresh(true);
    },
    setMinutes: function(minutes) {
        this.minutes = minutes;
        this.refresh(true);
    },
    setTime: function(time) {
        this.time = time;
        this.refresh(false);
    },
    setDays: function(days) {
        this.days = days;
        this.refresh(true);
    },
    getHours: function() {
        return this.hours;
    },
    getMinutes: function() {
        return this.minutes;
    },
    getTime: function() {
        return this.time;
    },
    getDays: function() {
        return this.days;
    },
    toString: function() {
        return this.hours + ':' + this.minutes;
    }
};