Apple’s iCal ( ), included with OS X, is easy to use—and its price can’t be beat. But it’s not especially powerful or flexible, and the improvements Apple has made to it in recent years have been fairly minor. If you’ve been frustrated by iCal’s limitations or are looking for a scheduling program with a little more oomph, BusyMac’s BusyCal may be just what you need.

BusyCal builds on the foundation of the company’s well-regarded BusySync software ( ), which lets you sync calendars between users (and not merely between the same user’s accounts on multiple Macs, as is the case with MobileMe). But whereas BusySync relies on iCal for entry and display of calendar items, BusyCal replaces iCal with a program that has a familiar look and feel but a wide range of new features.

Indeed, BusyCal looks startlingly similar to iCal, and if you’re not paying careful attention, you may forget that you’re in a different program. At the same time, BusyCal's take on iCal’s user interface sports numerous subtle changes that, taken together, dramatically improve the experience of tracking one’s schedule.

For starters, when adding or editing an event in BusyCal, you don't need to open a separate window or double-click an event and then click an Edit button (as you do in iCal)—all the controls you need are immediately visible in a configurable Info panel at the side of the window when you select an event. In addition to details such as start and end times, alarms, notes, and attachments, events can include user-defined tags, graphics, and styled text.

The main calendar view can display not only a single day, a week, or a month at a time, but also a two-week period, an arbitrary seven-day or five-week period (say, from Wednesday through Tuesday or mid-November through mid-December), or a sortable, scrolling list of all events. In addition, in the week or month view, you can scroll through the items for any given day if there are more than can fit in the existing view. BusyCal includes built-in options to display a five-day weather forecast and moon phases on your calendar.

To-do items in BusyCal vastly improve on iCal's. Tasks with due dates (either single or repeating items) can appear on the calendar itself as well as in their own list, and can carry forward to the next day automatically if not completed. BusyCal also offers new event types, such as sticky notes, banners, and journal entries—all of which can be shared with other users.

My favorite improvement on iCal, however, is the alert window that appears when an alarm sounds. You can snooze an alarm (with a user-selectable delay) or dismiss it—and you can do all this, even for multiple events at a time, by using the keyboard if you prefer.

BusyCal’s core syncing features work just as well as in BusySync, keeping events in sync with other Macs, Google Calendar, or both, and letting you optionally set passwords for others to read or write to any shared calendar. (Because BusyCal uses the same underlying technology as BusySync, you can freely mix and match the two, although only one or the other can run on any given Mac.) BusyCal uses iCal’s storage mechanism for calendar data, so BusyCal and iCal remain automatically in sync, and BusyCal events can synchronize with an iPhone or iPod touch by way of MobileMe or iTunes. Unfortunately, because iCal doesn’t support BusyCal’s novel event types (such as sticky notes and banners), such events won’t sync from one computer to another on the same account via MobileMe, making it potentially awkward to find a configuration that works as well for one person with multiple Macs as for two or more people with a single Mac each.

As much of an improvement as it is on iCal, BusyCal can do better in some areas. For example, it offers read-only access to CalDAV and Exchange calendars (whereas iCal lets you write to them too), has minimal AppleScript support compared with iCal, and does not offer calendar groups. It also lacks the kind of mini-month view iCal has. (BusyMac says calendar groups and mini-month views will be available soon in a free upgrade, that improved AppleScript support is planned, and that write support for CalDAV and Exchange is under consideration.) But considering how much better BusyCal is in virtually every other area, these are minor complaints.

Macworld’s buying advice

BusyCal addresses almost every common complaint about iCal, adds useful new features, and yet maintains the same simple interface and ease of use Mac users are accustomed to. The program is overkill for users with simple calendaring needs who have never found iCal limiting, but for anyone who needs to share calendars or wants a wider range of scheduling options, BusyCal is an ideal choice.

[Senior Contributor Joe Kissell is the senior editor of TidBits and author of numerous e-books about OS X.]