date.js

// Date library

var log4js = require('log4js'),
    log = log4js.getLogger('Date'),
    fmts = {
    
    // Returns the full day of the week (e.g. Sunday)
    'A' : function (d) {
        var day = d.getUTCDay();
        
        if (day === 0)
        {
            return 'Sunday';
        }
        else if (day === 1)
        {
            return 'Monday';
        }
        else if (day === 2)
        {
            return 'Tuesday';
        }
        else if (day === 3)
        {
            return 'Wednesday';
        }
        else if (day === 4)
        {
            return 'Thursday';
        }
        else if (day === 5)
        {
            return 'Friday';
        }
        else if (day === 6)
        {
            return 'Saturday';
        }
        else
        {
            throw day + " doesn't appear to be a valid day.";
        }
    },
    
    // Returns the truncated day of the week (e.g. Sun)
    'a' : function (d) {
        return fmts['A'](d).substr(0, 3);
    },
    
    // Returns day of the month (e.g. 5, 17, 20)
    'e' : function (d) {
        return d.getUTCDate();
    },
    
    // Returns zero-padded day of the month (e.g. 05, 17 20)
    'd' : function (d) {
        var day = fmts['e'](d);
        
        if (day < 10)
        {
            return "0" + day;
        }
        return day;
    },
    
    // Not implemented
    'j' : function (d) {
        throw "%j not implemented";
    },
    
    // Returns the day of the week (0-6)
    'u' : function (d) {
        return d.getUTCDate();
    },
    
    // Returns the day of the week (0-6)
    'w' : function (d) {
        return d.getUTCDate();
    },
    
    // Not implemented
    'U' : function (d) {
        throw "%U not implemented";
    },
    
    // Not implemented
    'W' : function (d) {
        throw "%W not implemented";
    },
    
    // Not implemented
    'V' : function (d) {
        throw "%V not implemented";
    },
    
    // Returns the month of the year (e.g. 3, 8, 12)
    'n' : function (d) {
        return d.getUTCMonth();
    },
    
    // Returns the zero padded month of the yar (e.g. 03, 08, 12)
    'm' : function (d) {
        var month = fmts['n'](d);
        
        if (month < 10)
        {
            return "0" + month;
        }
        return month;
    },
    
    // Not implemented
    'h' : function (d) {
        throw "%h not implemented";
    },
    
    // Returns the full month name (e.g. July)
    'B' : function (d) {
        var month = fmts['n'](d);
        
        if (month === 0)
        {
            return 'January';
        }
        else if (month === 1)
        {
            return 'February';
        }
        else if (month === 2)
        {
            return 'March';
        }
        else if (month === 3)
        {
            return 'April';
        }
        else if (month === 4)
        {
            return 'May';
        }
        else if (month === 5)
        {
            return 'June';
        }
        else if (month === 6)
        {
            return 'July';
        }
        else if (month === 7)
        {
            return 'August';
        }
        else if (month === 8)
        {
            return 'September';
        }
        else if (month === 9)
        {
            return 'October';
        }
        else if (month === 10)
        {
            return 'November';
        }
        else if (month === 11)
        {
            return 'December';
        }
        else
        {
            throw month + " doesn't appear to be a valid month.";
        }
    },
    
    // Return shortend month (e.g. Jul)
    'b' : function (d) {
        return fmts['B'](d).substr(0, 3);
    },
    
    // Returns the full year (e.g. 1980)
    'Y' : function (d) {
        return d.getUTCFullYear();
    },
    
    // Returns the last two digits of a year (e.g. 80)
    'y' : function (d) {
        return String(fmts['y'](d)).substr(2, 2);
    },
    
    // Returns zero-padded minutes
    'M' : function (d) {
        var m = d.getUTCMinutes();
        
        if (m < 10)
        {
            m = "0" + m;
        }
        
        return m;
    },
    
    // Returns the number of seconds since epoch
    's' : function (d) {
        return d.getTime() / 1000 | 0;
    },
    
    // Returns the number of seconds, zero padded
    'S' : function (d) {
        var seconds = d.getSeconds();
        
        if (seconds < 10)
        {
            return "0" + seconds;
        }
        
        return seconds;
    },
    
    // Returns the English ordinal suffix for the day of the month, 2 characters
    'c' : function (d) {
        var day = fmts['e'](d);
        
        if (day === 1 || day === 21 || day === 31)
        {
            return 'st';
        }
        else if (day === 2 || day === 22)
        {
            return 'nd';
        }
        else if (day === 3 || day === 23)
        {
            return 'rd';
        }
        else if ((day >= 4 && day <= 20) || (day >= 24 && day <= 30))
        {
            return 'th';
        }
        else
        {
            throw day + " does not appear to be a valid day (1-31)";
        }
    },
    
    // Returns hours in military time
    'k' : function (d) {
        return d.getUTCHours();
    },
    
    // Returns zero-padded hours in military time
    'H' : function (d) {
        var h = fmts['k'](d);
        
        if (h < 10)
        {
            h = "0" + h;
        }
        
        return h;
    },
    
    // Returns timezone
    'z' : function (d) {
        var hours = Math.floor(d.getTimezoneOffset() / 60),
            op = "+";
        
        if (hours > 0)
        {
            op = '-';
        }
        
        hours = Math.abs(hours);
        
        if (hours < 10)
        {
            hours = "0" + hours;
        }
        
        return '-' + hours + '00';
    },
    
    'Z' : function (d) {
        var hours = Math.floor(d.getTimezoneOffset() / 60),
            op = "+";
        
        if (hours > 0)
        {
            op = '-';
        }
        
        hours = Math.abs(hours);
        
        if (hours < 10)
        {
            hours = "0" + hours;
        }
        
        return op + hours + ':00';
    },
    
    'T' : function (d) {
        return fmts['H'](d) + ':' + fmts['M'](d) + ':' + fmts['S'](d) + ' ' + fmts['z'](d);
    }
};

log.setLevel('FATAL');

module.exports = function (d) {
    var init,
        self = this;
    
    // Check to see if we were passed a `Date` object.
    if (d instanceof Date) 
    {
        return arguments.callee(d.getTime());
    }
    
    if (typeof d !== 'undefined')
    {
        init = d;
    }
    else
    {
        init = new Date().getTime();
    }
    
    this.time = function () {
        return init;
    };
    
    this.obj = function () {
        return new Date(init);
    };
    
    this.format = function (fmt) {
        // Parse date format
        var opts = fmt.split('%'),
            ret = opts[0],
            l = opts.length;
        
        log.trace('Parsing ' + fmt + ' into ' + l + ' parts (' + opts.join('%') + ').');
        
        // Iterate over options.
        for(var i = 1; i < l; i++)
        {
            log.trace('Formatting ' + opts[i] + ' as ' + opts[i].substr(0, 1));
            ret += fmts[opts[i].substr(0,1)](this.obj()) + opts[i].substr(1, opts[i].length);
        }
        return ret;
    };
    
    return this;
};