CalFusion: A New Expression of the Calendar Paradigm

We are so accustomed to our current view of time that it is difficult to appreciate the cultural shift that came with the idea of viewing time as uniform units between fixed points. Though clock technology existed in Asia previously, the Western view of time is more closely connected to the use of clocks in medieval monasteries "with their need for a rule and for synchronized order to guide communal life" (McLuhan 146). Clock technology afforded the change of time from a personal experience to a shared one, and allowed sleeping, eating and other activities to be scheduled according to outside rather than "organic" needs (McLuhan 146). From the communal bell clock that permitted communities to act as a unit by presenting an external signal, to small clocks and watches that allowed owners to determine the time and consequently modify their own actions, clocks both created a need to schedule group activities and the means to do so.

Group calendar systems likewise can be used for personal or social scheduling. Though simple in function, group calendar systems do all of the calendar work of traditional paper or personal electronic calendars; additionally, they allow informal communication between users through the scheduling and viewing of group events.

What does CalFusion do?

The CalFusion email browser combines browser functionality with a distributed calendar to allow users to track personal and group events more effectively. Event announcement email messages sent through CalFusion are given special headers that allow them to be placed on a centralized calendar; users can then access the system through their web browsers and seamlessly display different groups' calendars or an overlay of multiple groups. Users can also view the original email messages that correspond to events on the currently loaded calendar.

Who will use CalFusion?

CalFusion was originally designed for use by SIMS students, staff, and faculty to reduce scheduling confusion resulting from mass dissemination of event notices via email. First-year students adapting to the rigorous SIMS schedule have a special need for this type of system. The CalFusion prototype serves a much broader user base; it is ideally suited to small or mid-sized organizations or community groups whose members wish to centralize their scheduling in one easily accessible location. Our working model is designed as a public system without added security measures; our goal is to maintain its web-based, non-proprietary nature and allow users to access it at their own discretion. However, future implementations could include security measures such as encryption, password protection, or a system administrator to limit calendar use to a defined group.

Scenarios of Use

Case #1
Joe attends the SIMposium weekly talks. He wishes to invite all regular attendees to a social event following the next talk. He opens his web browser to CalFusion and composes an email message using the Post Event form. He chooses the SIMposium group from the pull-down list; after he sends the email, the event will be posted onto the SIMposium group calendar, where all group members can read it.

Case #2
Sally also attends the SIMposium talks. She notices Joe's event posted on the calendar. She thinks she might have a conflict, so she chooses to display a combination of Joe's group and her other groups. By placing all events on the calendar together, she quickly realizes she does have a scheduling conflict. CalFusion visually displays the conflict; Sally is responsible for choosing which event to attend.

Case #3
Professor X just cancelled his class for the next three weeks to take an extended European vacation. Instead of emailing the student list in the traditional fashion, X posts his notice on each cancelled class day. When his students check the calendar for class events, they will see his note and schedule their weeks accordingly. If the students forget the length of his absence, they can easily check the original notice as often as needed; instead of being lost in their email inboxes, the notice is prominently displayed on the appropriate weeks as a reminder.


CalFusion, written entirely in Perl and HTML, consists of two primary modules: User Interface (UI) and Web Data / File Management (WDFM).

The UI is a crossbreed of original and borrowed code. Building primarily on the functionality of HyperCal, a CGI-based calendar system (coded by R.C. Bowen), the CalFusion UI allows the user to carry out four main actions: posting an event in CalFusion format; displaying events for a given day; displaying events for a given month; and displaying the full text of the original email message. Message sets are displayed according to the group selected by the user; the "Combination" option allows the user to overlay events from multiple groups.

The WDFM, implemented with new code, catalogues data relevant to the calendar by accessing a series of e-mail accounts, extracting specific information, and saving it to a flat file corresponding to each account. The collection script runs periodically to ensure fresh data.

The UI, rather than accessing email accounts directly, reads calendar data from the flat files prepared by the WDFM module.

Click here for the complete system architecture.

Comparison to Existing Systems

CalFusion, unlike email clients such as Netscape Messenger or Eudora, is completely web-based. It does not require special software or plug-ins to run-only a standard web browser (Explorer recommended). Unlike services such as Hotmail or YahooMail, CalFusion is advertisement-free and not-for-profit. It is not a proprietary application; organizations can adapt the software to fit their own needs.

Unlike a listserv system, CalFusion lets the user view events within a calendar framework rather than in the order email messages arrive. CalFusion is a visual application, allowing the user to view events from a variety of different groups together on one calendar. The user can modify and customize the display for ease of use, viewing one group event list or combinations of multiple event lists.

CalFusion is a stand-alone application that requires minimal system administration. It functions as a pull rather than a push model; the user can decide what to do, and the calendar facilitates but does not mediate.

Possible Future Work

In its current form, CalFusion provides an open forum for communication. This base can be expanded to promote negotiation and collaboration within work groups and between geographically-separated parties. For instance, decision-making functions could be implemented to allow each user to rank their preference for date and time. Also, the functionality could be enhanced to include a planning mechanism incorporating RSVP or rescheduling suggestions.

Another highly desirable enhancement would be to allow the user to create a personalized overlay view incorporating only those events or accounts that he/she selects. This enhancement would require a personal login or password.

Ideally, CalFusion could be integrated with a standard email browser, allowing the user to have full email and time management functionality in one location.

An enhanced graphical representation of the CalFusion event schedule could display the events of a given date in a quickly comprehensible format. For example, a month view might display variations in shading on each day according to the number of events scheduled on that day, allowing the user to instantly see which days are full or open.

These are only a few of the many directions possible for future CalFusion development. Having successfully implemented a core set of functionality, we look forward to exploring these extensions and enhancing our prototype.


McLuhan, Marshall. Understanding Media: The Extensions of Man McGraw Hill, 1964

Palen, Leysia. "Social, Individual & Technological Issues for Groupware Calendar Systems", CHI '99 (15-20 May 1999): 17-24