{
  "$schema": "http://json-schema.org/draft-04/schema#",
  "id": "timePeriod.json#",
  "type": "object",
  "description": "A span of time represented by a starting date-time and an ending date-time.",
  "example": "../examples/timePeriod.json",
  "minProperties": 1,
  "additionalProperties": true,

  "properties": {
    "id": {
      "type": "string",
      "description": "A unique identifier for a time period.",
      "translation": {
        "ISO 19115-2": ["EX_TemporalExtent > extent > TimePeriod @id"]
      }
    },
    "description": {
      "type": "string",
      "description": "A brief description providing relevant information about the time period.",
      "translation": {
        "ISO 19115-2": ["EX_TemporalExtent > extent > TimePeriod > description "]
      }
    },
    "identifier": {
      "$ref": "./identifier.json#",
      "description": "Identifier for the timePeriod."
    },
    "periodName": {
      "type": "array",
      "description": "Names associated with the time period.",
      "translation": {},
      "minItems": 1,
      "items": {
        "type": "string"
      }
    },
    "startDateTime": {
      "description": "Starting date, or date and time.",
      "translation": {
        "ISO 19115-2": ["EX_TemporalExtent > extent > TimePeriod > beginPosition "],
        "FGDC CSDGM": ["idinfo > timeperd > rngdates > begdate"]
      },
      "$ref": "common.json#/definitions/date"
    },
    "endDateTime": {
      "description": "Ending date, or date and time.",
      "translation": {
        "ISO 19115-2": ["EX_TemporalExtent > extent > TimePeriod > endPosition"],
        "FGDC CSDGM": ["idinfo > timeperd > rngdates > enddate"]
      },
      "$ref": "common.json#/definitions/date"
    },
    "timeInterval": {
      "$ref": "#/definitions/timeInterval"
    },
    "duration": {
      "$ref": "#/definitions/duration"
    }
  },
  "anyOf": [{
    "title": "startDateTime required",
    "required": ["startDateTime"]
  }, {
    "title": "endDateTime required",
    "required": ["endDateTime"]
  }],
  "definitions": {
    "duration": {
      "type": "object",
      "description": "Object for collecting information about a duration or period of time.",
      "example": "../examples/duration.json",
      "translation": {},
      "minProperties": 1,
      "additionalProperties": true,
      "properties": {
        "years": {
          "$ref": "#/definitions/durationPart"
        },
        "months": {
          "$ref": "#/definitions/durationPart"
        },
        "days": {
          "$ref": "#/definitions/durationPart"
        },
        "hours": {
          "$ref": "#/definitions/durationPart"
        },
        "minutes": {
          "$ref": "#/definitions/durationPart"
        },
        "seconds": {
          "$ref": "#/definitions/durationPart"
        }
      }
    },
    "durationPart": {
      "type": "integer"
    },
    "timeInterval": {
      "type": "object",
      "description": "Defines a length of time in specific units.",
      "example": "../examples/timeInterval.json",
      "translation": {},
      "required": ["interval", "units"],
      "additionalProperties": true,
      "properties": {
        "interval": {
          "type": "integer",
          "description": "The amount of time.",
          "translation": {}
        },
        "units": {
          "enum": ["year", "month", "day", "hour", "minute", "second"],
          "description": "The unit of time for the interval.",
          "translation": {}
        }
      }
    }
  }
}