CalConnect XXXVII - September 12-16, 2016

CalConnect Developers' Forum - Monday-Wednesday
CalConnect Conference - Wednesday-Friday

CalConnect XXXVII in Dresden, Germany hosted by dmfs
CalConnect XXXVII in Dresden, September 12-16 2016, hosted by dmfs
Monday, September 12, 2016 to Friday, September 16, 2016
Subscribe to the CalConnect Week Calendar.
Recent Changes: 

4 August 2016 - Detailed Conference Schedule  and Topics added

17 August 2016 - Event Reading Lists updated for CalConnect XXXVII at

23 August 2016 - Event week calendar .ics file published

08 September 2016 - Minor schedule revisions to Conference

CalConnect XXXVII, consisting of a CalConnect Developers' Forum (Interoperability Testing and technical discussions of specifications and issues) and a CalConnect Conference (Members Meeting)  will be held in Dresden on September 12-16, 2016, hosted by dmfs, makers of SmoothSync.

The Developers' Forum will take place all day Monday and Tuesday September 12-13, and Wednesday morning, ending before lunch.  The Conference will open following lunch on Wednesday, and will run through Thursday and Friday. 

Developers' Forum and Interoperability Test Event: The Developers' Forums are open to both members and non-members as participants or as observers; please see Test Event  for both basic  information about the event and for the schedule and agenda  (this will be developed gradually over the summer, so check back periodically).

Please Note: You do not need finished or polished code to participate in the IOP testing; in fact as soon as you have something working at all, testing against other participants can help debugging and code development, especially in identifying red herrings and wrong decisions.

Conference: The Conference will offer a variety of sessions on technical and higher-level topics, informal BOFs (Birds of a Feather sessions), plus additional sessions and committee meetings. All attending member representatives and observers are welcome.

The last session on Friday afternoon will be the full Plenary meeting of the Consortium, open to all participants. This session will include future directions for Technical Committees, and establishment of future goals and directions for the Consortium. 


International Visitors 

In general most CalConnect participants will not require a Visa to visit Germany.  However if you are unsure , please see German VISA Information.

Conference Details 

Breakfast is included with your room at the Schloss.  Morning coffee, lunch, and morning and afternoon breaks will be served to all participants in the Developers' Forum and Conference and are included in your registration fees. The Monday and Thursday group dinners are hosted by CalConnect. The Wednesday Reception is hosted by dmfs GmbH (SmoothSync), our hosts for CalConnect XXXVII.

Dress at all CalConnect events is casual to business casual.

Registration Information 

Registration is now open for CalConnect XXXVI; please see to register for the developers' forum/test event and/or the conference. Note that you must register separately for the forum/test event and for the conference, however you may request a single invoice and payment.



The Developers' Forum/Test Event (September 12-14) and the Conference (September 14-16) will be held at Schloss Eckberg, Bautzner Straße 134, 01099 Dresden, Germany.  Schloss Eckberg is also the conference hotel for CalConnect XXXVII.  The Schloss is on a hill next to the river Elbe, and is a short tram ride from the center of Dresden.This map shows the location of the Schloss:,13.7972523,17z/data=!4m2!3m1!1s0x4709c8c376138fad:0x7d37734c04fb0fc8?hl=en

The meeting room will be in the conference facility of the Schloss and will be announced closer to the event.


Airport Information:  Dresden is served by Dresden International Airport.  Service is offered between Dresden and several European destinations, largely German (however Zurich is also served).  Dresden does not offer any intercontinental flights at this time, so if you are coming from another continent you will have to transfer or shift transortation modes. 

Unfortunately, Schloss Eckberg does not at this time offer a shuttle service, but are contemplating one (we have been advised to check with them later this summer).  If they do institute a shuttle service we will update this page with more information. 

Taxi service: a taxi to or from the airport costs about €25.  Please be aware that taxi drivers usually only accept cash, and there is no Uber service in Dresden.

Public Transportation:  Travel between the airport and the hotel may easily be done by a combination of train and tram.  Please see   The trams cost €2.30; there are ticket machines in the tram, but you need coins to get a ticket.  There is no ticket machine on the train from the airport, but there is one in the station.  Optionally you may purchase a week ticket for €21, which is also valid for the train to and from the airport; you may purchase this ticket at the airport station when you arrive. 

The trams also offer a convenient way to get getween the Schloss and the city; please see


Our conference hotel and meeting venue is  Schloss Eckberg, Bautzner Straße 134, 01099 Dresden, Germany.

The Schloss is on a hill next to the river Elbe, and is a short tram ride from the center of Dresden.This map shows the location of the Schloss:,13.7972523,17z/data=!4m2!3m1!1s0x4709c8c376138fad:0x7d37734c04fb0fc8?hl=en.

The venue is surrounded by a park and across the street is a forest, which is nice for the runners amongst us.  As noted the venue is not located in the center of the city, but there is a tram to the center every 10 minutes; it takes about 20 minutes between the venue and the center. 

We are offered a conference room rate, inclusive of breakfast each morning, either in the Kavaliershaus (a separate hotel building) at €93 per night, or in the Castle itself at a rate of €143 per night.

In order to obtain our conference rate, you must book either by telephone at +49 351 8099-0 or by e-mail to When booking you will need to provide the following information:

  • Full name and address
  • E-mail address
  • Conference Code:  CalConnect
  • Arrival and departure dates
  • Arrival time if after 6:00 p.m.
  • Room preference (in Castle or Kavaliershaus; single or double) (there is no extra charge for a double room)
  • Credit Card information (if you are not comfortable sending this via e-mail you can call them instead, or after doing e-mail for the rest of the booking)

Check-in is after 3:00 p.m.; Departure is by 11:00 a.m.

Lodging Tax:  The City of Dresden charges a lodging tax; see  However business travelers may apply for a refund or, if the professional nature of the trip can be declared beforehand, the lodging facility will not charge the tax. 

If you are staying at the Conference Hotel, you will not be charged the lodging tax, our host has arranged this already with the Schloss. 

If you are not staying at the Schloss and wish to avoid the lodging tax, please download and complete this form and bring it with you: 




Test Event Schedule 

The Developers Forum and Interoperability Test Event begins at 0800 Monday morning and runs all day Monday and Tuesday, plus Wednesday morning.


Monday 12 September
0800-0830 Coffee & Rolls
0830-1000 Testing
1000-1030 Break and Refreshments
1030-1230 Testing
1230-1330 Lunch
1330-1430 BOF or Testing
1430-1530 Testing
1530-1600 Break and Refreshments
1600-1800 Testing

1915-2130 Test Event Dinner (TBA)

Tuesday 13 September
0800-0830 Coffee & Rolls
0830-1000 Testing
1000-1030 Break and Refreshments
1030-1230 Testing
1230-1330 Lunch
1330-1430 BOF or Testing
1330-1530 Testing
1530-1600 Break and Refreshments
1600-1800 Testing

Wednesday 14 September
0800-0830 Coffee & Rolls
0830-1000 Testing
1000-1030 Break and Refreshments
1030-1130 Testing
1130-1200 Wrap-up
1200 End of IOP Testing

1230-1330 Lunch


Test Event Agenda 

Specific Areas for testing as identified by participants

Current specific testing areas include
  • Sharing
  • CalDAV
  • CardDAV
  • iMIP
  • API <--> iCalendar
  • Calendar publication and subscription models

Technical Topics for Developers' Discussions

The developer discussions provide an opportunity for those who may not have been able to get on calls to engage other developers in detailed discussions.
These discussions can cover implementation approaches, protocol issues,  data models etc.  and may involve the entire group or small breakout sessions.
The schedule for these discussions will be decided on during the 2.5days and is very flexible.
Current discussion topics include
  • vPoll
  • Syncing Collections
  • Subscription models and their relation to sharing
  • TC API work

Please see the Reading List for the Developer's Forum at

Baseline Testing

Final determination of what will be tested will depend on what the participants in the test event wish to test; the current set of interests is noted above. Participants may also request to test things that are not mentioned in this list (the registration form offers a place to indicate areas you wish to test). In all cases at least two participating organizations must be interested in testing a particular area or scenario to form testing pairs.

Please note that you do not need finished or polished code to participate in the testing; in fact as soon as you have something working at all, testing against other participants can help debugging and code development, especially in identifying red herrings and wrong decisions.

Possible Testing areas

  • CalDAV testing:
    • Access (basic operations of CalDAV)
    • Scheduling
    • Sync report (depth: 1 on home collection)
    • Mobile
    • Sharing
    • Prefer Header
  • Managed Attachments
  • iSchedule:
    • Server discovery
    • DKIM security
  • Timezones:
    • Service Protocol
    • Timezones by Reference
  • Calendar Alarms:
    • Snooze
    • Default alarms
  • VPOLL support in clients and servers
  • VAVAILABILITY support in clients and servers
  • Autodiscovery protocol
  • Non-gregorian calendar recurrences via RRULE and RSCALE
  • iCalendar:
    • Rich text and other new properties (and hashing)
  • iMIP
  • iTIP
  • jCal, the JSON format for iCalendar - libraries and servers
  • xCal, the XML format for iCalendar
  • Enhanced VTODO support
  • CardDAV testing:
    • Generic
    • Sync report
    • Mobile
    • vCard 4

Who May Participate or Observe

Any vendor or organization wishing to test a calendaring and scheduling implementation, or a mobile calendaring server or client, is welcome to participate whether or not they are a CalConnect member. Note that CalConnect members receive a substantial discount on their Interoperability Test Event registration fee.

Any vendor or organization wishing to observe the Interoperability Test Event is welcome whether or not they are a CalConnect. Note that an organization, member or not, may only observe one Test Event. 


Please see CalConnect Interoperability Test Event Registration Fees for information about event registration fees. Please choose one of the following registration methods:

Interoperability Event Scenarios

If you are planning to participate, please contact us to let us know which interoperability event scenarios you wish to pursue or if you would like to propose a new scenario.

CalConnect will invite all registered participants to two or three conference calls prior to the event to discuss logistics, testing scenarios, etc. 



Conference Schedule 



Wednesday 14 September
1100-1200 Introduction to CalConnect Q&A
An optional session for first-time attendees. The genesis of CalConnect, a brief history, and how CalConnect works, followed by questions.
1230-1330 Lunch
1330-1430 Conference Opening
Welcome, Logistics, Introductions, Test Event Reports, Technical Committee activity since last CalConnect event, Conference Schedule Review
1430-1500 New Member and Non-Member Presentations
Introductory presentations from new members or non-members at their first CalConnect event.
1500-1530 Categorization and Event Types
Being able to categorize events in a standardized manner will help in aggregation and allow applications to discover events of interest.  This session will discuss the use of DMOS categorization.  TC EVENTPUB.
1530-1600 Break and Refreshments
1600-1700 iSCHEDULE
Are we prepared and determined enough to drive iSchedule to warrant the work that needs to happen in CalConnect and the IETF. TC ISCHEDULE.
1700-1800 Topics from Developer's Forum
1800-2000 Welcome Reception
On Premises
Thursday 15 September
0800-0830 Coffee & Rolls
0830-0900 CalConnect Specifications at the IETF
Status of specifications and open discussion with an IETF representative
0900-0930 Calendaring Developer's Guide
The guide has recently been published at  This session will discuss how to attract authors to provide additional content, as well as identify important areas of content to develop.  TC DEVGUIDE.
0930-1030 iMIP Current Issues
There are a number of problems with the current iMIP model and implementations, leading to interoperability issues. We will discuss the issues, possible solutions, and identify best practices for the Developer's Guide. TC IMIP.
1030-1100 Break and refreshments
1100-1230 API - A new representation for Calendar Data
The API Technical Committee is defining a new representation for calendar data that is more palatable to current developers, especially in the web community. This session will review the current status of the effort and consider otustanding issues. TC API
1230-1330 Lunch
1330-1430 DAV-Based Resource Sharing
We will review the progress made in redefining CalDAV Sharing as a DAV-based standard resource sharing specification with CalDAV and CardDAV extensions.  TC SHARING.
1430-1530 Alternative Subsciption Models
Current subscriptions usually involve clients downloading an .ics file at cdertain intervals.  We will discuss alternative approaches including a mechanism by which clients can "upgrade" to a better connection, e.g. a CalDAV subset.  TC CALDAV.
1530-1600 Break and refreshments
1600-1700 CalDAV Current Topics
We will review recent extensions to CalDAV such as supporting the new JSON API data format and discuss possible unanticipated issues.  TC CALDAV.
1700-1800 Open Discussion:  The Future of Calendaring and CalConnect
Topics will include CalConnect in Asia, Calendaring augmenting other phenomena in your life (e.g. Tesla), Calendaring and the Internet of Things, Time-related initiatives external to CalConnect, and others.
1915-2200 Conference Dinner
Restaurant Lingnerterassen (2 minute walk, in Lingerschloss) 
Friday 16 September
0800-0830 Coffee & Rolls
0830-0930 Review of iCalendar Extensions and VAVAILABILITY specifications
Review and encourage use of new iCalendar features defined in iCalendar Extensions and VAVAILABILITY specifications
0930-1000 Provisional Committee on Security and Privacy
Review charter, goals, progress and status of PC SEC and encourage more participation
1000-1030 Provisional Committee on visual vCard (vCard data in QRCODEs)
Review charter, goals, progress and status of PC QR and encourage more participation
1030-1100 Break and refreshments
1100-1200 PATCH/DIFF/COMPACT for iCalendar data
A new proposed mechanism by which calendar data can be updated in place rather than the current GET/PUT full replacement approach. In many cases this will result in a significant decrease in data transferred.
Review of the automated service discovery specification for standards-based implementations plus next steps and possible implementations
1230-1330 Lunch
1330-1430 BOF (Birds of a Feather) Discussions
1430-1445 Technical Committee Directions for period to CalConnect XXXVIII
1445-1530 CalConnect Plenary Meeting
Administrative business, coming events, consensus agreements on decisions reached during the week, open floor.
1530 Close of CalConnect XXXVII

Please see the Reading List for the Conference at