The below is taken form iCal's Help files. It seems the suggestion is to create events with title like "Meet Bob at 1pm on Friday".
Here are some additional ways to add events:
- Add an event in Day or Week view by dragging from the event’s start time to its end time.
- Add a new 1-hour event in Day or Week view by double-clicking within the day you want the event to appear, at the event’s start time.
- Add a new event in Month view by double-clicking within the day you want the event to appear. Enter a name and time duration for the event in the event’s title field, and then press Return.iCal moves the event to the correct time and sets it to the correct duration. For example, you can double-click within a day in Month view, enter “Movie 7-9pm,” and then press Return.If you don’t enter a time duration, iCal sets the event’s duration to 1 hour.If you don’t enter any time information, iCal makes the event an all-day event.
For anyone still reading this thread, the solution to the problem is to use the command-line interface by clicking on the plus button. You'll have to figure out what language it considers natural. Not all possible phrasing will get the desired results. I don't know about anyone else, but I prefer a GUI to a command line anyday.