To add a schedule to your MAC's calendar/calendar software in ICal, you'll need to "open ical-Select Date-Right-click Add-fill content and time-and so on" to such a complex process. The latest Lion system greatly improves the intelligence of ical, and when you click on "+" to add a new schedule, just enter a paragraph like "Meet Tomorrow 10 o'clock in the morning" and ICal will automatically create a schedule/to-do item titled "Meeting" and the time is 10:00 next day. Of course, not necessarily tomorrow, Friday, x months x days and other time words can be.
Apple developed the Cow x Word segmentation technology to bring us a lot of convenience, and I tried, even if not to enter a specific time, but instead of "Morning", "noon", "Night" the word, ICal will default to the time set to 9:00, 12:00, 20:00. "Half an hour later" This relative time ICal can also recognize and automatically add the schedule correctly.