Date

A date object. This is not a Datetime. It is just a date -- meaning that it refers to a non-relative date like a birthdate.

JSON representation 
{
  "year": string,
  "month": string,
  "day": string
}
Fields
year

string (Int64Value format)

REQUIRED: The year portion of the date.
month

string (Int64Value format)

REQUIRED: The month portion of the date. January is 1, February is 2, and so on.
day

string (Int64Value format)

REQUIRED: The day portion of the date. The first day of the month is 1.