iCal: Your Powerful Personal Assistant

When you add an event to your iCal calendar, you can do much more than simply name it and specify a date and time. Like a good personal assistant, it can remind you of upcoming events, help round up others for meetings, and even ensure that you have essential files in front of you at just the right moment.
To access iCal’s hidden superpowers, just double-click on the event’s name (or select it and type Command-i), then click the Edit button.

To invite other participants to an iCal event, just type their email addresses into the Attendees field. If you prefer, you can open iCal’s Addresses panel by typing Command-Option-a, and drag names from your contacts list. When you’ve added the desired contacts and event details, click Send, and Apple Mail will email the event request. If the event changes, you can send an update with the revised information.

There are many options here. For example, you can assign customized, color-coded categories to help keep track of work projects, personal appointments, and other commitments. You can set up recurring events via the repeat menu, which allows for custom recurrences (say, the last Tuesday of May every ten years) in addition to daily, weekly, monthly, and annual events. To create an event that continues over one or more days, click the “all-day” checkbox.
You can ask iCal to remind you of your upcoming events through a powerful alarm function, which issues one or more event reminders via pop-up messages or email. When pop-up reminders appear, you can “snooze” them for as little as one minute or as much as a week. You can even schedule the iCal alarm to automatically run a script or open a file on your computer at a specified time.

You can also attach documents, graphics, or other files to an event — pictures, maps, spreadsheets, or whatever — and include any relevant URLs. Finally, you can insert additional text into the Note field: anything from a phone number to an entire meeting agenda. (Though this field initially displays as a narrow strip, you can type or paste in as much text as you like.)
When you’re finished, click Done. All the data you added will appear next time you double-click on the event.