This section covers all data-entry and command usage details that may not have been fully elucidated in the preceding scenarios.

2.10.1. Date Formats

Ed. Note: I think it would be quite good to summarize these requirements in tabular form, with one table for each class of dialog, with one table row for each data-entry field in the dialog.

The following data entry formats apply to any scheduling dialog where the indicated field appears:

1. The Title and Location fields are free-form, one-line strings. If the text is longer than will fit in the provided data-entry area, then it will automatically scroll as the user types and can be repositioned using the normal text movement arrow keys or such other forms of horizontal scrolling as may be available on a particular implementation platform.

2. The (Start) Date and End Date are type-in fields, with checking for legal date syntax. The following are legal forms of date entry: ...

If the user specifies a recurring event without checking any box in the additional recurring information, the event will be set by default to recur weekly, on the day of the week that is specified for the start date of the event. [Sketch: some other defaults are made clear by default display of selection box.]

Also explain what the standard defaults are for the settings of all dialog fields and note that these default settings can be changed in the by editing preferences.

2.10.3. Required Fields

When scheduling or changing an item, the following fields are required to be non-empty and properly formated: Title, (Start) Date, Start Time, and Duration. If one or more of these fields is missing when the user presses the 'OK' or 'Change' button, the system responds with the error dialog shown in Figure 63.

The first five commands in the 'View' menu apply to a user-selected target in the calendar display, or to a default target. To select a viewing target, the user clicks on a desired location somewhere in the current display window. The "current display window" is defined precisely as the display window most recently generated by the system or the window most recently made current by the user having clicked on it or selecting it in the 'View Windows' menu. The following are the specific details for how a viewing target is selected in the current display window:

For the 'View Item' command, an item is selected as follows:

1. In a day, week, or month view, the user selects a scheduled item by clicking anywhere on the time range or title of the item.

2. An item cannot be selected in a year view, since no times or titles are displayed there.

3. If no item is explicitly selected by the user, the default is the first item, if any, scheduled on today's date. If there is no such item, then the 'View Item' command has no effect. (The exact system response to commands with no effect is described in Section 2.11.1 on error conditions.)

For the 'View Day' command, a day is selected as follows:

1. In a table- or list-style week view, the user selects a day by clicking on any of the day names that label the table columns, or on any item in a desired day.

2. In a list-style week view, a month view, or a year view, the user selects a day by clicking on the numeric date of any day, or on any item in a desired day.

3. If the current display window is a day view, the 'View Day' command has no effect.

4. If no day is explicitly selected by the user, the default is today's date.

For the 'View Week' command, a week is selected as follows:

1. In a day view, the selected week is the one that contains the currently displayed day.

2. In a month or year view, the user selects a week by clicking on the numeric date of any day within the desired week, or on any item in a day within the desired week.

3. If the current display window is a table-style week view, the 'View Week Table' command has no effect; if the current display window is a list- style week view, the 'View Week Lists' command has no effect.

4. If no week is explicitly selected by the user, the default is the week containing today's date.

For the 'View Month' command, a month is selected as follows:

1. In a day or week view, the selected month is the one that contains the currently displayed day or week.

2. In a year view, the user selects a month by clicking on the name of any month or on the date of any day within the month.

3. If the current display window is a month view, the 'View Month' command has no effect.

4. If no month is explicitly selected by the user, the default is the month containing today's date.

1. In a day, week, or month view, the selected year is the one that contains the currently displayed day, week, or month.

2. If the current display window is a year view, the 'View Year' command has no effect.

3. If no year is explicitly selected by the user, the default is the year containing today's date.

In all of the cases where a name or numeric date is selected, the system confirms the selection by highlighting the name or date in reverse video. For example, Figure 64 shows how the system highlights the date of September 1 when the user clicks on that date number in the monthly display.

The system provides a three-way option to control the scheduling of items with overlapping times. The option settings are the following:

1. disallow overlapping times entirely

2. allow overlapping times, with warning

3. allow overlapping times, no warning