Total Organizer help.

Working with schedule (calendar)

To Add a new calendar (schedule) item, go to the "Schedule" tab, and press Ctrl+N, or click the "Create new item" button. Alternatively - double click a cell where you want to put your new task.

You can specify start and end date & time. If you want you can specify the reminder time.

"Auto remove" checkbox: if checked, the item will be removed 24h after its end time. It is useful for tasks like "Watch a movie tomorrow at..." or "My co-worker wants to talk to me at 13 am". After 24 hours it doesn't matter if you completed the task - the movie is over (you saw it or not), and your co-worker wanted to talk today at 13 am, not tomorrow. So, if you think Total Organizer shouldn't remember the task so long, click the checkbox.

About reminders

You can set them in Task edit dialogs.

A few notes:

If you simply close the reminder (by clicking the "X" in the window, or pressing Escape) then the reminder will show up again in about 15 minutes
If you close the application/shutdown the computer, while having one or more reminders open, those reminders will of course show up again next time the program is open.
In case of recurring tasks (repeating e.g. every day), the "Don't remind again" button removes only one repetition, so, if the tasks is repeating every day - you will see a new reminder the next day.

FAQ:

Q: I closed the application then reopen it (or closed the reminder(s) window only) and I don't see a reminder again!
A: Don't worry, it will appear. It may take a minute or 15 minutes. The only way to successfully remove a reminder is to click the "don't remind again" button - any other reason which caused the reminder to close (closing an application, closing the reminder window by e.g. pressing 'Escape') removes the reminder only temporarily. They are quite stubborn.

Related

Editing items (common characteristics)