MongoDB Dayofonth
{ $dayOfMonth: new Date("2016-01-01") }
// result: 1
{ $dayOfMonth: { date: new Date("Jan 7, 2003") } }
//result: 7
Tiny Coders
{ $dayOfMonth: new Date("2016-01-01") }
// result: 1
{ $dayOfMonth: { date: new Date("Jan 7, 2003") } }
//result: 7