https://www.sironaconsulting.com/timestamp.js

1/** timestamp namespaced methods **/
2var __wbTs = (function() {
3    function _split_timestamp(timestamp) {
4        if(typeof timestamp == "number") {
5            timestamp = timestamp.toString();
6        }
7        return [
8            timestamp.slice(-14, -10),
9            timestamp.slice(-10, -8),
10            timestamp.slice(-8, -6),
11            timestamp.slice(-6, -4),
12            timestamp.slice(-4, -2),
13            timestamp.slice(-2)
14        ];
15    }
16    var MONTHS_LONG = [
17	"January", "February", "March", "April", "May", "June",
18	"July", "August", "September", "October", "November", "December"
19    ];
20    var MONTHS_SHORT = [
21	"Jan", "Feb", "Mar", "Apr", "May", "Jun", "Jul", "Aug", "Sep",
22	"Oct", "Nov", "Dec"
23    ];
24    var FIELDS = {
25	'Y': function(d) { return d.getUTCFullYear() },
26	'm': function(d) { return d.getUTCMonth() + 1 },
27	'b': function(d) { return MONTHS_SHORT[d.getUTCMonth()] },
28	'B': function(d) { return MONTHS_LONG[d.getUTCMonth()] },
29	'd': function(d) { return d.getUTCDate() },
30	'H': function(d) { return ('0'+d.getUTCHours()).slice(-2) },
31	'M': function(d) { return ('0'+d.getUTCMinutes()).slice(-2) },
32	'S': function(d) { return ('0'+d.getUTCSeconds()).slice(-2) },
33	'%': function() { return '%' }
34    };
35    function timestamp2datetime(timestamp) {
36            var ts_array = _split_timestamp(timestamp);
37            return new Date(Date.UTC(
38		ts_array[0], ts_array[1]-1, ts_array[2],
39		ts_array[3], ts_array[4], ts_array[5]
40	    ));
41    }
42    return {
43	timestamp2datetime: timestamp2datetime,
44	getMonthName: function(mon) {
45	    return MONTHS_LONG[mon];
46	},
47	format: function(timestamp, fmt) {
48	    return fmt.replace(/%./g, function(ph) {
49		var field = FIELDS[ph[1]];
50		return field ? field(timestamp2datetime(timestamp)) : ph;
51	    });
52	}
53    }
54})();