moment({ year :2010, month :3, day :5, hour :15, minute :10, second :3, millisecond :123});
moment({ years:2010, months:3, date:5, hours:15, minutes:10, seconds:3, milliseconds:123});

You can create a moment by specifying some of the units in an object.

and date key both mean day-of-the-month.

String values (as shown on the last line) are supported from version2.11.0.