{
  "$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": {
      "$ref": "./identifier.json#",
      "description": "Identifier for the timePeriod."
    },
    "periodName": {
      "type": "array",
      "description": "Names associated with the time period.",
      "translation": {},
      "items": {
        "type": "string"
      }
    }
  },
  "oneOf": [{
    "title": "dateTime",
    "type": "object",
    "description": "A timePeriod with a startDateTime and/or endDateTime.",
    "example": "../examples/timePeriod.json#/0",
    "properties": {
      "startDateTime": {
        "description": "Starting date, or date and time.",
        "translation": {
          "ISO 19115-2": ["EX_TemporalExtent > extent > TimePeriod > beginPosition "],
          "FGDC CSDGM": ["idinfo > timeperd > rngdates > begdate"]
        },
        "$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": {
        "$ref": "#/definitions/duration"
      }
    },
    "anyOf": [{
      "title": "startDateTime required",
      "required": ["startDateTime"]
    }, {
      "title": "endDateTime required",
      "required": ["endDateTime"]
    }]
  }, {
    "title": "geologicAge",
    "type": "object",
    "description": "A timePeriod with a startGeologicAge and/or endGeologicAge.",
    "example": "../examples/timePeriod.json#/1",
    "properties": {
      "startGeologicAge": {
        "$ref": "./geologicAge.json#",
        "description": "A name, code, or date for the beginning of an event or period in geologic time.",
        "translation": {
          "FGDC CSDGM": ["timeperd > timeinfo > rngdates > beggeol"]
        }
      },
      "endGeologicAge": {
        "$ref": "./geologicAge.json#",
        "description": "A name, code, or date for the end of an event or period in geologic time.",
        "translation": {
          "FGDC CSDGM": ["timeperd > timeinfo > rngdates > endgeol"]
        }
      }
    },
    "anyOf": [{
      "title": "startGeologicAge required",
      "required": ["startGeologicAge"]
    }, {
      "title": "endGeologicAge required",
      "required": ["endGeologicAge"]
    }]
  }],
  "definitions": {
    "duration": {
      "type": "object",
      "description": "Object for collecting information about a duration or period of time.",
      "example": "../examples/duration.json",
      "translation": {},
      "minProperties": 1,
      "additionalProperties": true,
      "properties": {
        "years": {
          "$ref": "#/definitions/durationPart"
        },
        "months": {
          "$ref": "#/definitions/durationPart"
        },
        "days": {
          "$ref": "#/definitions/durationPart"
        },
        "hours": {
          "$ref": "#/definitions/durationPart"
        },
        "minutes": {
          "$ref": "#/definitions/durationPart"
        },
        "seconds": {
          "$ref": "#/definitions/durationPart"
        }
      },
      "anyOf": [{
        "title": "years is required",
        "required": ["years"]
      }, {
        "title": "months is required",
        "required": ["months"]
      }, {
        "title": "days is required",
        "required": ["days"]
      }, {
        "title": "hours is required",
        "required": ["hours"]
      }, {
        "title": "minutes is required",
        "required": ["minutes"]
      }, {
        "title": "seconds is required",
        "required": ["seconds"]
      }]
    },
    "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": "number",
          "description": "The amount of time.",
          "translation": {}
        },
        "units": {
          "enum": ["year", "month", "day", "hour", "minute", "second"],
          "description": "The unit of time for the interval.",
          "translation": {}
        }
      }
    }
  }
}