| JSON data formats for vCard and iCalendar | P. Kewisch |
| Internet-Draft | Mozilla |
| Intended status: Standards Track | C. Daboo |
| Expires: July 10, 2018 | Apple, Inc. |
| M. Douglass | |
| RPI | |
| January 6, 2018 |
jCal: The JSON format for iCalendar
draft-ietf-jcardcal-jcal-09
This specification defines "jCal", a JSON format for iCalendar data. The iCalendar data format is a text format for capturing and exchanging information normally stored within a calendaring and scheduling application, for example tasks and events. JSON is a lightweight, text-based, language-independent data interchange format commonly used in internet applications.
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The iCalendar data format [RFC5545] is a widely deployed interchange format for calendaring and scheduling data. While many applications and services consume and generate calendar data, iCalendar is a specialized format that requires its own parser/generator. In contrast, JSON-based formats as defined in [RFC4627] are the native format for JavaScript widgets and libraries and it is appropriate to have a standard form of calendar data that is easier to work with than iCalendar.
The purpose of this specification is to define "jCal", a JSON format for iCalendar data. jCal is defined as a straightforward mapping into JSON from iCalendar, so that iCalendar data can be converted to JSON, and then back to iCalendar, without losing any semantic meaning in the data. Anyone creating jCal calendar data according to this specification will know that their data can be converted to a valid iCalendar representation as well.
The key design considerations are essentially the same as those for [RFC6321], that is:
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in [RFC2119].
The underlying format used for jCal is JSON. Consequently, the terms "object" and "array" as well as the four primitive types (strings, numbers, booleans, and null) are to be interpreted as described in Section 1 of [RFC4627].
Some examples in this document contain "partial" JSON documents used for illustrative purposes. In these examples, three periods "..." are used to indicate a portion of the document that has been removed for compactness.
This section describes how iCalendar data is converted to jCal using a simple mapping between the iCalendar data model and JSON elements.
In [RFC5545], iCalendar objects are comprised of a set of "components", "properties", "parameters" and "values". The top level of iCalendar data typically contains a stream of iCalendar objects, each of which can be considered a "component". A "component" can contain other "components" or "properties". A "property" has a "value" and a set of zero or more "parameters". Each of these entities have a representation in jCal, defined in the following sections. The representation of a iCalendar object in JSON will be named "jCal object" throughout this document.
iCalendar uses a line folding mechanism to limit lines of data to a maximum line length (typically 75 octets) to ensure maximum likelihood of preserving data integrity as it is transported via various means (e.g., email) - see Section 3.1 of [RFC5545].
iCalendar data uses an "escape" character sequence for text values and property parameter values. See Section 3.1 and 3.3 of [RFC5545] as well as [RFC6868].
When converting from iCalendar to jCal, first iCalendar lines MUST be unfolded. Afterwards, any iCalendar escaping MUST be unescaped. Finally JSON escaping (e.g., for control characters) MUST be applied.
The reverse order applies when converting from jCal to iCalendar. First, JSON escaping MUST be unescaped. Afterwards, iCalendar escaping MUST be applied. Finally, long lines SHOULD be folded as described in [RFC5545].
iCalendar uses a base64 encoding for binary data. However, it does not restrict the encoding from being applied to non-binary value types. So the following rules are applied when processing a property with the "ENCODING" property parameter set to "BASE64":
When base64 encoding and decoding is used, it MUST conform to Section 4 of [RFC4648], which is the base64 method used in [RFC5545].
One key difference in the formatting of values used in iCalendar and jCal is that in jCal the specification uses date/time values aligned with the extended format of [ISO.8601.2004], which is more commonly used in internet applications that make use of the JSON format. The sections of this document describing the various date and time formats contain more information on the use of the complete representation, reduced accuracy or truncated representation.
At the top level of the iCalendar object model is an "iCalendar stream". This stream encompasses multiple "iCalendar objects". As the typical use case is transporting a single iCalendar object, there is no defined equivalent to an "iCalendar stream" in jCal. To transport multiple jCal objects in a stream, a simple JSON array can be used.
Example:
["vcalendar", [ /* Add jCal properties in place of this comment */ ], [ /* Add jCal components in place of this comment */ ] ]
Each iCalendar component, delimited by "BEGIN" and "END", will be converted to a fixed length array with three fields that have a specific structure:
This mapping applies to the top level iCalendar objects, as well as individual sub-components in the same way. The iCalendar to jCal component mapping is valid for both current iCalendar components and any new iCalendar components added in the future. Conversion is to be done in the same way.
While the grouping of properties and sub-components does not retain the original order specified in the iCalendar data, the semantics of a component are preserved.
Example:
["vevent", [ /* Add jCal properties in place of this comment */ ], [ /* Add jCal components in place of this comment */ ] ]
iCalendar properties, whether they apply to the "VCALENDAR" object or to a component, are handled in a consistent way in the jCal format.
Each individual iCalendar property is represented in jCal by an array with three fixed elements, followed by one or more additional elements, depending on if the property is a multi-value property as described in Section 3.1.2 of [RFC5545].
The array consists of the following fixed elements: [RFC5545] Section 3.1.2, each value is another element, and there can be any number of additional elements.
The remaining elements of the array are used for one or more values of the property. For single-value properties, the array has exactly four elements; for multi-valued properties, as described in
In the following example, the "categories" property is multi-valued and has two values, while the summary property is single-valued:
Example:
["vevent",
[
["summary", {}, "text", "Meeting with Fred"],
["categories", {}, "text", "Meetings", "Work"]
...
],
[ /* sub-components */ ]
]
This section describes some properties that have special handling when converting to jCal.
In iCalendar, the "GEO" property value is defined as a semi-colon separated list of two "FLOAT" values, the first representing latitude and the second longitude.
In jCal, the value for the "geo" property value is represented as an array of two values. The first value of the property represents the latitude, the second value represents the longitude.
When converting from jCal to iCalendar, the two values MUST be converted using a semi-colon as the separator character.
Example
["vevent",
[
["geo", {}, "float", [ 37.386013, -122.082932 ] ]
...
],
...
]
In iCalendar, the "REQUEST-STATUS" property value is defined as a semi-colon separated list of two or three "TEXT" values. The first represents a code, the second a description, and the third any additional data.
In jCal, the value for the "request-status" property value is represented as an array with two or three values. The first array element corresponds to the code, the second element corresponds to the description and the third element corresponds to the additional data. Each value is represented using a string value. If there is no additional data in the iCalendar value, the last element of the array SHOULD NOT be present.
When converting from jCal to iCalendar, the two or three values MUST be converted using a semi-colon as the separator character.
iCalendar Example:
BEGIN:VEVENT ... REQUEST-STATUS:2.0;Success REQUEST-STATUS:3.7;Invalid calendar user;ATTENDEE: mailto:jsmith@example.com ... END:VEVENT
jCal Example:
["vevent":
[
["request-status", {}, "text", ["2.0", "Success"] ],
["request-status", {}, "text",
[
"3.7",
"Invalid calendar user",
"ATTENDEE:mailto:jsmith@example.org"
]
],
...
],
...
]
Property parameters are represented as a JSON object where each key-value pair represents the iCalendar parameter name and its value. The name of the parameter MUST be in lowercase, the original case of the parameter value MUST be preserved. For example, the "PARTSTAT" property parameter is represented in jCal by the "partstat" key. Any new iCalendar parameters added in the future will be converted in the same way.
Example:
["vevent":
[
["attendee",
{
"partstat": "ACCEPTED",
"rsvp": "TRUE",
"role": "REQ-PARTICIPANT"
},
"cal-address",
"mailto:jsmith@example.org"
],
["summary", {}, "text", "Meeting"],
...
],
...
]
iCalendar defines a "VALUE" property parameter (Section 3.2.20 of [RFC5545]). This property parameter MUST NOT be added to the parameters object. Instead, the value type is signaled through the type identifier in the third element of the array describing the property. When converting a property from iCalendar to jCal, the value type is determined as follows:
Converting from jCal into iCalendar is done as follows:
See Section 5 for information on handling unknown value types.
In [RFC5545], some parameters allow using a COMMA-separated list of values. To ease processing in jCal, the value to such parameters MUST be represented in an array containing the separated values. The array elements MUST be string values. Single-value parameters can be represented either using a single string value or an array with one string element. A jCal parser MUST be able to understand both value data types. An example for a such parameter is the iCalendar "DELEGATED-FROM" and "DELEGATED-TO" parameter, more such parameters may be added in extensions.
The iCalendar specification requires encapsulation between DQUOTE characters if a parameter value contains a colon, a semicolon or a comma. These extra DQUOTE characters do not belong to the actual parameter value, and hence are not included when the parameter is converted to jCal.
Example 1:
["attendee",
{
"delegated-to": ["mailto:jdoe@example.org",
"mailto:jqpublic@example.org"]
},
"cal-address",
"mailto:jsmith@example.org"
]
Example 2:
["attendee",
{
"delegated-to": "mailto:jdoe@example.org"
},
"cal-address",
"mailto:jsmith@example.org"
]
The following subsections specify how iCalendar property value data types, which are defined in the subsections of [RFC5545] Section 3.3, are represented in jCal.
["attach", {}, "binary", "SGVsbG8gV29ybGQh"]
["x-non-smoking", {}, "boolean", true]
["attendee", {}, "cal-address", "mailto:kewisch@example.com"]
date = year "-" month "-" day ;YYYY-MM-DD
["dtstart", {}, "date", "2011-05-17"]
date-complete = year "-" month "-" day ;YYYY-MM-DD time-complete = hour ":" minute ":" second [zone] ; HH:MM:SS datetime = date-complete "T" time-complete
["dtstart", {}, "date-time", "2012-10-17T12:00:00"],
["dtstamp", {}, "date-time", "2012-10-17T12:00:00Z"],
["dtend",
{ "tzid": "Europe/Berlin" },
"date-time",
"2011-10-17T13:00:00"
]
["duration", {}, "duration", "P1D"]
["x-grade", {}, "float", 1.3]
["percent-complete", {}, "integer", 42]
["freebusy",
{ "fbtype": "FREE" },
"period",
["1997-03-08T16:00:00Z", "P1D"]
]
["rrule",
{},
"recur",
{
"freq": "YEARLY",
"count": 5,
"byday": [ "-1SU", "2MO" ],
"bymonth": 10
}
]
["rrule",
{},
"recur",
{
"freq": "MONTHLY",
"interval": 2,
"bymonthday": [ 1, 15, -1 ],
"until": "2013-10-01"
}
]
["comment", {}, "text", "hello, world"]
time-complete = hour ":" minute ":" second [zone] ; HH:MM:SS
["x-time-local", {}, "time", "12:30:00"],
["x-time-utc", {}, "time", "12:30:00Z"],
["x-time-offset", { "tzid": "Europe/Berlin" }, "time", "12:30:00"]
["tzurl", {}, "uri", "http://example.org/tz/Europe-Berlin.ics"]
["tzoffsetfrom", {}, "utc-offset", "-05:00"],
["tzoffsetto", {}, "utc-offset", "+12:45"]
iCalendar extension properties and property parameters (those with an "X-" prefix in their name) are handled in the same way as other properties and property parameters: the property is represented by an array, the property parameter represented by an object. The property or parameter name uses the same name as for the iCalendar extension, but in lowercase. For example, the "X-FOO" property in iCalendar turns into the "x-foo" jCal property. See Section 5 for how to deal with default values for unrecognized extension properties or property parameters.
When converting component, property and property parameter values, the names SHOULD be converted to uppercase. Although iCalendar names are case insensitive, common practice is to keep them all uppercase following the actual definitions in [RFC5545].
Character escaping and line folding MUST be applied to the resulting iCalendar data as required by [RFC5545] and [RFC6868].
Non-binary value types MUST NOT be base64 encoded.
When converting to iCalendar, the VALUE parameter MUST be added to properties whose default value type is unknown, but do not have a jCal type identifier "unknown". The VALUE parameter MAY be omitted for properties using the default value type. The VALUE parameter MUST be omitted for properties which have the jCal type identifier "unknown".
In iCalendar, properties can have one or more value types as specified by their definition, with one of those values being defined as the default. When a property uses its default value type, the "VALUE" property parameter does not need to be specified on the property. For example, "DTSTART"'s default value type is "DATE-TIME", so "VALUE=DATE-TIME" need not be set as a property parameter. However, "DTSTART" also allows a "DATE" value to be specified, and if that is used, "VALUE=DATE" has to be set as a property parameter.
When new properties are defined or "X-" properties used, an iCalendar to jCal converter might not recognize them, and not know what the appropriate default value types are, yet they need to be able to preserve the values. A similar issue arises for unrecognized property parameters.
In jCal, a new "unknown" property value type is introduced. Its purpose is to allow preserving unknown property values when round-tripping between jCal and iCalendar. To avoid collisions, this specification reserves the UNKNOWN property value type in iCalendar. It MUST NOT be used in any iCalendar as specified by [RFC5545], nor any extensions to it. The type is hence registered to the iCalendar Value Data Types registry in Section 7.1.
Any property that does not include a "VALUE" property parameter and whose default value type is not known, MUST be converted to a primitive JSON string. The content of that string is the unprocessed value text. Also, value type MUST be set to "unknown".
To correctly implement this format, it is critical that if the default type is not known that the type "unknown" is used. If this requirement is ignored and for example "text" is used, additional escaping may occur which breaks round-tripping values.
Any unrecognized property parameter MUST be converted to a string value, with its content set to the property parameter value text, treated as if it were a "TEXT" value.
In jCal the value type is always explicitly specified. It is converted to iCalendar using the iCalendar VALUE parameter, except in the following two cases:
The following is an example of an unrecognized iCalendar property (that uses a "DATE-TIME" value as its default), and the equivalent jCal representation of that property.
iCalendar:
X-COMPLAINT-DEADLINE:20110512T120000Z
jCal:
["x-complaint-deadline", {}, "unknown", "20110512T120000Z"]
The following is an example of how to cope with jCal data where the parser was unable to identify the type. Note how the "unknown" value type is not added to the iCalendar data and escaping, aside from standard JSON string escaping, is not processed.
jCal:
["x-coffee-data", {}, "unknown", "Stenophylla;Guinea\\,Africa"]
iCalendar:
X-COFFEE-DATA:Stenophylla;Guinea\,Africa
The following is an example of a jCal property (where the corresponding iCalendar property uses a "INTEGER" value as its default), and the equivalent iCalendar representation of that property.
jCal:
["percent-complete", {}, "integer", 95]
iCalendar:
PERCENT-COMPLETE:95
The following is an example of an unrecognized iCalendar property parameter (that uses a "FLOAT" value as its default) specified on a recognized iCalendar property, and the equivalent jCal representation of that property and property parameter.
iCalendar:
DTSTART;X-SLACK=30.3;VALUE=DATE:20110512
jCal:
["dtstart", { "x-slack": "30.3" }, "date", "2011-05-12"]
This specification defines how iCalendar data can be "translated" between two different data formats - the original text format and JSON - with a one-to-one mapping to ensure all the semantic data in one format (properties, parameters and values) are preserved in the other. It does not change the semantic meaning of the underlying data itself, or impose or remove any security considerations that apply to the underlying data.
The use of JSON as a format does have its own inherent security risks as discussed in Section 7 of [RFC4627]. Even though JSON is considered a safe subset of JavaScript, it should be kept in mind that a flaw in the parser processing JSON could still impose a threat which doesn't arise with conventional iCalendar data.
With this in mind, a parser for JSON data should be used for jCal that is aware of the security implications. For example, the use of JavaScript's eval() function is only allowed using the regular expression in Section 6 of [RFC4627]. A native parser with full awareness of the JSON format should be preferred.
In addition, it is expected that this new format will result in iCalendar data being more widely disseminated (e.g., with use in web applications rather than just dedicated calendaring applications).
In all cases, application developers have to conform to the semantics of the iCalendar data as defined by [RFC5545] and associated extensions, and all of the security considerations described in Section 7 of [RFC5545], or any associated extensions, are applicable.
This document defines a MIME media type for use with iCalendar in JSON data. This media type SHOULD be used for the transfer of calendaring data in JSON.
IANA is asked to add the following entry to the iCalendar Data Types registry:
IANA is asked to make the "Status" column for this entry in the registry say, "Reserved - Do not use" and to make the "Reference" column refer to Section 5 of this document.
The authors would like to thank the following for their valuable contributions: William Gill, Erwin Rehme, and Dave Thewlis, Simon Perreault, Michael Angstadt, Peter Saint-Andre, Bert Greevenbosch, Javier Godoy. This specification originated from the work of the XML-JSON technical committee of the Calendaring and Scheduling Consortium.
| [calconnect-artifacts] | The Calendaring and Scheduling Consortium, "Code Artifacts and Schemas" |
| [RFC4627] | Crockford, D., "The application/json Media Type for JavaScript Object Notation (JSON)", RFC 4627, DOI 10.17487/RFC4627, July 2006. |
| [RFC6982] | Sheffer, Y. and A. Farrel, "Improving Awareness of Running Code: The Implementation Status Section", RFC 6982, DOI 10.17487/RFC6982, July 2013. |
This section records the status of known implementations of the protocol defined by this specification at the time of posting of this Internet-Draft, and is based on a proposal described in [RFC6982]. The description of implementations in this section is intended to assist the IETF in its decision processes in progressing drafts to RFCs. Please note that the listing of any individual implementation here does not imply endorsement by the IETF. Furthermore, no effort has been spent to verify the information presented here that was supplied by IETF contributors. This is not intended as, and must not be construed to be, a catalog of available implementations or their features. Readers are advised to note that other implementations may exist.
According to [RFC6982], "this will allow reviewers and working groups to assign due consideration to documents that have the benefit of running code, which may serve as evidence of valuable experimentation and feedback that have made the implemented protocols more mature. It is up to the individual working groups to use this information as they see fit".
Additionally, interoperability testing of this draft is an ongoing effort under members of calconnect, the Calendaring and Scheduling Consortium. CalDAV Vendors are looking into supporting this draft.
Below is an ABNF schema as per [RFC5234] for iCalendar in JSON. ABNF Symbols not described here are taken from [RFC4627]. The schema is non-normative and given for reference only.
The numeric section numbers given in the comments refer to section in [RFC5545]. Additional semantic restrictions apply, especially regarding the allowed properties and sub-components per component. Details on these restrictions can be found in this document and [RFC5545].
Additional schemas may be available on the internet at [calconnect-artifacts].
; A jCal Object is a component with the component-name "vcalendar".
; Restrictions to which properties and sub-components may be
; specified are to be taken from RFC5545.
jcalobject = component
; A jCal component consists of the name string, properties array and
; component array
component = begin-array
DQUOTE component-name DQUOTE value-separator
properties-array value-separator
components-array
end-array
components-array = begin-array
[ component *(value-separator component) ]
end-array
; A jCal property consists of the name string, parameters object,
; type string and one or more values as specified in this document.
property = begin-array
DQUOTE property-name DQUOTE value-separator
params-object value-separator
DQUOTE type-name DQUOTE
propery-value *(value-separator property-value)
end-array
properties-array = begin-array
[ property *(value-separator property) ]
end-array
; Property values depend on the type-name. Aside from the value types
; mentioned here, extensions may make use of other JSON value types.
; The non-terminal symbol structured-prop-value covers the special
; cases for GEO and REQUEST-STATUS
property-value = simple-prop-value / structured-prop-value
simple-prop-value = string / number / true / false
structured-prop-value =
begin-array
[ structured-element *(value-separator structured-element) ]
end-array
structured-element = simple-prop-value
; The jCal params-object is a JSON object which follows the semantic
; guidelines described in this document.
params-object = begin-object
[ params-member *(value-separator params-member) ]
end-object
params-member = DQUOTE param-name DQUOTE name-separator param-value
param-value = string / param-multi
param-multi = begin-array
[ string *(value-separtor string) ]
end-array
; The type MUST be a valid type as described by this document. New
; value types can be added by extensions.
type-name = "binary" / "boolean" / "cal-address" / "date" /
"date-time" / "duration" / "float" / "integer" /
"period" / "recur" / "text" / "time" / "uri" /
"utc-offset" / x-type
; Component, property, parameter and type names MUST be lowercase.
; Additional semantic restrictions apply as described by this
; document and RFC5545.
component-name = lowercase-name
property-name = lowercase-name
param-name = lowercase-name
x-type = lowercase-name
lowercase-name = 1*(%x61-7A / DIGIT / "-")
This section contains two examples of iCalendar objects with their jCal representation.
BEGIN:VCALENDAR CALSCALE:GREGORIAN PRODID:-//Example Inc.//Example Calendar//EN VERSION:2.0 BEGIN:VEVENT DTSTAMP:20080205T191224Z DTSTART:20081006 SUMMARY:Planning meeting UID:4088E990AD89CB3DBB484909 END:VEVENT END:VCALENDAR
["vcalendar",
[
["calscale", {}, "text", "GREGORIAN"],
["prodid", {}, "text", "-//Example Inc.//Example Calendar//EN"],
["version", {}, "text", "2.0"]
],
[
["vevent",
[
["dtstamp", {}, "date-time", "2008-02-05T19:12:24Z"],
["dtstart", {}, "date", "2008-10-06"],
["summary", {}, "text", "Planning meeting"],
["uid", {}, "text", "4088E990AD89CB3DBB484909"]
],
[]
]
]
]
BEGIN:VCALENDAR VERSION:2.0 PRODID:-//Example Corp.//Example Client//EN BEGIN:VTIMEZONE LAST-MODIFIED:20040110T032845Z TZID:US/Eastern BEGIN:DAYLIGHT DTSTART:20000404T020000 RRULE:FREQ=YEARLY;BYDAY=1SU;BYMONTH=4 TZNAME:EDT TZOFFSETFROM:-0500 TZOFFSETTO:-0400 END:DAYLIGHT BEGIN:STANDARD DTSTART:20001026T020000 RRULE:FREQ=YEARLY;BYDAY=-1SU;BYMONTH=10 TZNAME:EST TZOFFSETFROM:-0400 TZOFFSETTO:-0500 END:STANDARD END:VTIMEZONE BEGIN:VEVENT DTSTAMP:20060206T001121Z DTSTART;TZID=US/Eastern:20060102T120000 DURATION:PT1H RRULE:FREQ=DAILY;COUNT=5 RDATE;TZID=US/Eastern;VALUE=PERIOD:20060102T150000/PT2H SUMMARY:Event #2 DESCRIPTION:We are having a meeting all this week at 12 pm fo r one hour\, with an additional meeting on the first day 2 h ours long.\nPlease bring your own lunch for the 12 pm meetin gs. UID:00959BC664CA650E933C892C@example.com END:VEVENT BEGIN:VEVENT DTSTAMP:20060206T001121Z DTSTART;TZID=US/Eastern:20060104T140000 DURATION:PT1H RECURRENCE-ID;TZID=US/Eastern:20060104T120000 SUMMARY:Event #2 bis UID:00959BC664CA650E933C892C@example.com END:VEVENT END:VCALENDAR
["vcalendar",
[
["prodid", {}, "text", "-//Example Corp.//Example Client//EN"],
["version", {}, "text", "2.0"]
],
[
["vtimezone",
[
["last-modified", {}, "date-time", "2004-01-10T03:28:45Z"],
["tzid", {}, "text", "US/Eastern"]
],
[
["daylight",
[
["dtstart", {}, "date-time", "2000-04-04T02:00:00"],
["rrule",
{},
"recur",
{
"freq": "YEARLY",
"byday": "1SU",
"bymonth": 4
}
],
["tzname", {}, "text", "EDT"],
["tzoffsetfrom", {}, "utc-offset", "-05:00"],
["tzoffsetto", {}, "utc-offset", "-04:00"]
],
[]
],
["standard",
[
["dtstart", {}, "date-time", "2000-10-26T02:00:00"],
["rrule",
{},
"recur",
{
"freq": "YEARLY",
"byday": "1SU",
"bymonth": 10
}
],
["tzname", {}, "text", "EST"],
["tzoffsetfrom", {}, "utc-offset", "-04:00"],
["tzoffsetto", {}, "utc-offset", "-05:00"]
],
[]
]
]
],
["vevent",
[
["dtstamp", {}, "date-time", "2006-02-06T00:11:21Z"],
["dtstart",
{ "tzid": "US/Eastern" },
"date-time",
"2006-01-02T12:00:00"
],
["duration", {}, "duration", "PT1H"],
["rrule", {}, "recur", { "freq": "DAILY", "count": 5 } ],
["rdate",
{ "tzid": "US/Eastern" },
"period",
"2006-01-02T15:00:00/PT2H"
],
["summary", {}, "text", "Event #2"],
["description",
{},
"text",
// Note that comments and string concatenation are not
// allowed per JSON specification and is used here only
// to avoid long lines.
"We are having a meeting all this week at 12 pm for one " +
"hour, with an additional meeting on the first day 2 " +
"hours long.\nPlease bring your own lunch for the 12 pm " +
"meetings."
],
["uid", {}, "text", "00959BC664CA650E933C892C@example.com"]
],
[]
],
["vevent",
[
["dtstamp", {}, "date-time", "2006-02-06T00:11:21Z"],
["dtstart",
{ "tzid": "US/Eastern" },
"date-time",
"2006-01-02T14:00:00"
],
["duration", {}, "duration", "PT1H"],
["recurrence-id",
{ "tzid": "US/Eastern" },
"date-time",
"2006-01-04T12:00:00"
],
["summary", {}, "text", "Event #2"],
["uid", {}, "text", "00959BC664CA650E933C892C@example.com"]
],
[]
]
]
]