# Types Defines the primitive field types, including IDs, UUIDs, timestamps, and nulls, used consistently across REST API resources. > **The null value:** Unless otherwise noted, any field in the PagerDuty API can contain the value `null`. This represents the absence of a value for that field. For example, if a resource does not have a `description`, it may return `"description": null`. > Fields that are `required` will never be `null`. ## ID IDs are represented in the PagerDuty API as strings. All IDs will be contained within an `id` key. These IDs are not globally unique, but will be unique across a given endpoint. For example, a schedule and a service may both have the id `PSWK4Q7`, but no two schedules will have the same id. > **Note:** An `id` field is never `null`. ## UUID UUID fields are designated with the presence of `uuid` in their key name, and contain string ID values. UUIDs can be considered unique across PagerDuty. That is, no two resources of any type will share the same UUID. > **Note:** A `uuid` field is never `null`. ## String A standard JSON string. Strings in the REST API use the UTF-8 character set. ## Integer Integer types are a number without a fractional or decimal component. ## Boolean A boolean has only two possible states: true and false. In responses, booleans are always represented by native JSON booleans — `true` or `false` without quotes. In query strings, booleans can also be represented by string values. `"1"` and `"true"` are acceptable to represent a truthy value, and `"0"` and `"false"` are acceptable to represent a falsy value. > **Note:** A boolean field is never `null`. ## Array A standard JSON array. Arrays may contain any number of values, from `0` to `n`, unless otherwise specified. The primitive data type of the values within an array will always be consistent. That is, while a single array may contain objects representing both Users and Schedules, it will never contain both [objects](#object) and [integers](#integer). > **Note:** An array field is never `null`. > If there are no values for the associated field, the value will be an empty array (`[]`). ## Object A standard JSON object. Objects consist of string keys paired with values that may be of any type. ## DateTime All dates and times must be represented in the [ISO 8601](https://en.wikipedia.org/wiki/ISO_8601) date/time format. The time element is optional. Example dates in [ISO 8601](https://en.wikipedia.org/wiki/ISO_8601) format: | Date and Time | ISO 8601 Representation | | :------------------------------------------- | :---------------------- | | May 6th, 2011 at 5pm UTC | 2011-05-06T17:00Z | | May 6th, 2011 at 3:30am PDT | 2011-05-06T03:30-07 | | May 6th, 2011 at midnight (time is optional) | 2011-05-06 | ## Time Zone A string of a recognized time zone identifier. The acceptable identifiers and their name/description are shown below. | Time Zone Identifier | Name/Description | | :----------------------------- | :--------------------------- | | Africa/Algiers | West Central Africa | | Africa/Cairo | Cairo | | Africa/Casablanca | Casablanca | | Africa/Harare | Harare | | Africa/Johannesburg | Pretoria | | Africa/Monrovia | Monrovia | | Africa/Nairobi | Nairobi | | America/Argentina/Buenos_Aires | Buenos Aires | | America/Bogota | Bogota | | America/Caracas | Caracas | | America/Chicago | Central Time (US & Canada) | | America/Chihuahua | Chihuahua | | America/Denver | Mountain Time (US & Canada) | | America/Godthab | Greenland | | America/Guatemala | Central America | | America/Guyana | Georgetown | | America/Halifax | Atlantic Time (Canada) | | America/Indiana/Indianapolis | Indiana (East) | | America/Juneau | Alaska | | America/La_Paz | La Paz | | America/Lima | Lima | | America/Lima | Quito | | America/Los_Angeles | Pacific Time (US & Canada) | | America/Mazatlan | Mazatlan | | America/Mexico_City | Guadalajara | | America/Mexico_City | Mexico City | | America/Monterrey | Monterrey | | America/Montevideo | Montevideo | | America/New_York | Eastern Time (US & Canada) | | America/Phoenix | Arizona | | America/Puerto_Rico | Puerto Rico | | America/Regina | Saskatchewan | | America/Santiago | Santiago | | America/Sao_Paulo | Brasilia | | America/St_Johns | Newfoundland | | America/Tijuana | Tijuana | | Asia/Almaty | Almaty | | Asia/Baghdad | Baghdad | | Asia/Baku | Baku | | Asia/Bangkok | Bangkok | | Asia/Bangkok | Hanoi | | Asia/Chongqing | Chongqing | | Asia/Colombo | Sri Jayawardenepura | | Asia/Dhaka | Astana | | Asia/Dhaka | Dhaka | | Asia/Hong_Kong | Hong Kong | | Asia/Irkutsk | Irkutsk | | Asia/Jakarta | Jakarta | | Asia/Jerusalem | Jerusalem | | Asia/Kabul | Kabul | | Asia/Kamchatka | Kamchatka | | Asia/Karachi | Islamabad | | Asia/Karachi | Karachi | | Asia/Kathmandu | Kathmandu | | Asia/Kolkata | Chennai | | Asia/Kolkata | Kolkata | | Asia/Kolkata | Mumbai | | Asia/Kolkata | New Delhi | | Asia/Krasnoyarsk | Krasnoyarsk | | Asia/Kuala_Lumpur | Kuala Lumpur | | Asia/Kuwait | Kuwait | | Asia/Magadan | Magadan | | Asia/Muscat | Abu Dhabi | | Asia/Muscat | Muscat | | Asia/Novosibirsk | Novosibirsk | | Asia/Rangoon | Rangoon | | Asia/Riyadh | Riyadh | | Asia/Seoul | Seoul | | Asia/Shanghai | Beijing | | Asia/Singapore | Singapore | | Asia/Srednekolymsk | Srednekolymsk | | Asia/Taipei | Taipei | | Asia/Tashkent | Tashkent | | Asia/Tbilisi | Tbilisi | | Asia/Tehran | Tehran | | Asia/Tokyo | Osaka | | Asia/Tokyo | Sapporo | | Asia/Tokyo | Tokyo | | Asia/Ulaanbaatar | Ulaanbaatar | | Asia/Urumqi | Urumqi | | Asia/Vladivostok | Vladivostok | | Asia/Yakutsk | Yakutsk | | Asia/Yekaterinburg | Ekaterinburg | | Asia/Yerevan | Yerevan | | Atlantic/Azores | Azores | | Atlantic/Cape_Verde | Cape Verde Is. | | Atlantic/South_Georgia | Mid-Atlantic | | Australia/Adelaide | Adelaide | | Australia/Brisbane | Brisbane | | Australia/Darwin | Darwin | | Australia/Hobart | Hobart | | Australia/Melbourne | Canberra | | Australia/Melbourne | Melbourne | | Australia/Perth | Perth | | Australia/Sydney | Sydney | | Etc/GMT+12 | International Date Line West | | Etc/UTC | UTC | | Europe/Amsterdam | Amsterdam | | Europe/Athens | Athens | | Europe/Belgrade | Belgrade | | Europe/Berlin | Berlin | | Europe/Bratislava | Bratislava | | Europe/Brussels | Brussels | | Europe/Bucharest | Bucharest | | Europe/Budapest | Budapest | | Europe/Copenhagen | Copenhagen | | Europe/Dublin | Dublin | | Europe/Helsinki | Helsinki | | Europe/Istanbul | Istanbul | | Europe/Kaliningrad | Kaliningrad | | Europe/Kiev | Kyiv | | Europe/Lisbon | Lisbon | | Europe/Ljubljana | Ljubljana | | Europe/London | Edinburgh | | Europe/London | London | | Europe/Madrid | Madrid | | Europe/Minsk | Minsk | | Europe/Moscow | Moscow | | Europe/Moscow | St. Petersburg | | Europe/Paris | Paris | | Europe/Prague | Prague | | Europe/Riga | Riga | | Europe/Rome | Rome | | Europe/Samara | Samara | | Europe/Sarajevo | Sarajevo | | Europe/Skopje | Skopje | | Europe/Sofia | Sofia | | Europe/Stockholm | Stockholm | | Europe/Tallinn | Tallinn | | Europe/Vienna | Vienna | | Europe/Vilnius | Vilnius | | Europe/Volgograd | Volgograd | | Europe/Warsaw | Warsaw | | Europe/Zagreb | Zagreb | | Europe/Zurich | Bern | | Europe/Zurich | Zurich | | Pacific/Apia | Samoa | | Pacific/Auckland | Auckland | | Pacific/Auckland | Wellington | | Pacific/Chatham | Chatham Is. | | Pacific/Fakaofo | Tokelau Is. | | Pacific/Fiji | Fiji | | Pacific/Guadalcanal | Solomon Is. | | Pacific/Guam | Guam | | Pacific/Honolulu | Hawaii | | Pacific/Majuro | Marshall Is. | | Pacific/Midway | Midway Island | | Pacific/Noumea | New Caledonia | | Pacific/Pago_Pago | American Samoa | | Pacific/Port_Moresby | Port Moresby | | Pacific/Tongatapu | Nuku'alofa | ## URL A URL is a string that conforms to the [RFC 3986 syntax](https://tools.ietf.org/html/rfc3986). URLs are fully-qualified URIs that [provide a means of locating the resource](https://tools.ietf.org/html/rfc3986#section-1.1.3), and will never have only a subset of the URL, such as just a hostname or path. A number of URL validation libraries are available; any that conform to the spec should be able to correctly validate a URL field.