Purpose

To permit the attachment of calendar events (Date Alias Instances) to particular Calendar Instances

Note that two forms (this one, and CALF0511) achieve similar results. In this form, a number of events can be attached to one Calendar Instance. In CALF0511, one event can be attached to several different Calendar Instances.

Calendar Instance

This context block shows the Calendar Instance for which associated Date Alias Instances are displayed and/or maintained in the block below. When this form is entered via the button in the Maintain Calendar Types form, the context Calendar Instance is the one selected there. No inquiry on other Calendar Instances can be done directly in this form. It is necessary to return to the Maintain Calendar Types form and select another Calendar Instance there.

For example, the attachment of the event 'End of mid semester break' (END-BRK) to the Calendar Instance for 'Semester 1 2002' (SEM-1, 1/1/02, 30/6/02).

Date Alias Instance

The term 'Date Alias Instance' is used for an occurrence of a calendar event. Generally, to create a Date Alias Instance you need to:

• Assign a date to a Date Alias, and
• Attach it to a Calendar Instance.

The exception is for a calendar under development with a System Status of PLANNED. In this case, a date of occurrence is not required immediately but must be added before the Calendar Instance is made 'active'.

This block displays existing Date Alias Instances attached to the context Calendar Instance shown in the block below. These can be modified or deleted here, and new ones added.

Two date values can be displayed for each Date Alias record:

• The Absolute Value is the prescribed date of an event, entered using this form.
• The Alias Value is either the Absolute Value or a date calculated by Offset from another event. The entry in this field is generated by the System.

The Alias Value is the one recognised by the System as the value of the Date Alias Instance.

Date Alias Instance Offset

The date of an event (the Date Alias Instance) may be specified in terms of its relationship to another event (the 'base event'). The time difference between the two events is called the 'offset'. The 'base event' is termed the 'Offset Date Alias'.

It is possible to ensure that no matter what date is assigned to the offset Date Alias, the subject Date Alias Instance will not fall on specified days. This is achieved by specifying Offset Constraints in CALF0520, accessed via the button in this form.

This block is used for the creation, modification and display of offset information pertaining to the selected Date Alias Instance in the block above.

An Absolute Value overrides a calculated offset value where both are set. The Alias Value will reflect this.

For example, a Date Alias Instance for the end of semester 1 mid-semester break (END-BRK1) could be defined as occurring 8 days after the Date Alias Instance for the commencement of semester 1 mid-semester break (ST-BRK1). The Offset Date Alias is ST-BRK1, the Offset Duration of 8 days applies to END-BRK1.

Date Alias Instance Pair button

The pairing of Date Alias Instances indicates that the two dates plus every day between the two dates are represented by the relationship. When a Date Alias Instance pair is created using alias instances in calendars of category HOLIDAY, it effectively defines an institution break, one of the System Date Offset Constraint Types.

A pair relationship can also be defined at the Date Alias level in CALF0420.

For example, a Date Alias Instance ST-BREAK, 15/05/2003 is created in a calendar of category HOLIDAY, and it is paired with the Date Alias Instance END-BREAK, 30/05/2003, also in a holiday calendar, the System recognises the period 15/05/03 - 30/05/03 inclusive as an institution break.

Note: Altering the date of a Date Alias Instance will also alter the date of any Date Alias Instances which are offset from it.
Altering the Offset Duration of a Date Alias will also alter the date of any further Date Aliases which are offset from it.

This form is accessed through CALF0220, via the Date Alias Instances button (bottom centre).

The Calendar Instance block contains:

• Calendar Type
• Start Date
• End Date

The Date Alias Instance block contains:

• Date Alias
• Absolute Value
• Alias Value

  Button

  • Date Alias Instance Pair (overlay)
    • Related Date Alias
    • Calendar Type
    • Start Date
    • End Date
    • Related Alias Value
    • Back button

The Date Alias Instance Offset block contains:

• Offset Date Alias
• Calendar Type
• Start Date
• End Date
• Offset Alias Value
• Offset Duration
  • Days
  • Weeks
  • Months
  • Years

  Button

  • Offset Constraints (CALF0520)

Validations:

• A Census Date Alias Instance record cannot be deleted while an invoice record exists for a Government Loan Scheme and is due on that Census Date
• A Census Date Alias Instance record cannot be updated while an invoice record exists for a Government Loan Scheme and is due on that Census Date.

Date Alias Instance block

To add a new Date Alias Instance to the displayed Calendar Instance, using the Maintain Date Alias Instances form:

• Select any record in the Date Alias Instance block
• Enter Insert mode or select a blank record
• Select the desired Date Alias from the list of values in the Date Alias field
• Enter an Absolute Value , i.e. the date of occurrence of this instance, OR
• If the date of occurrence is to be defined by its relationship to another Date Alias Instance, then enter a Date Alias Instance offset (see Date Alias Instance Offset below)
• Save

Rules/Notes:

If a Date Alias Instance has a Calendar Category, it must match that of the Calendar Instance.

Dates must be assigned to all Date Alias Instances except where the Calendar Instance's System Calendar Status is PLANNED.

To modify the Absolute Value date of a Date Alias Instance for the displayed Calendar Instance, using the Maintain Date Alias Instances form:

• Find the Date Alias Instance to be modified
• Select the date to be changed
• Enter the new absolute date
• Save

Rules/Notes:

WARNING - If any other Date Alias Instances are offset from this one, altering this Date Alias Instance will also alter the instances which are offset.

To modify a date which is offset, use the instructions in Date Alias Instance Offset, below.

When entering an Absolute Value date for a Date Alias Instance which already has a date derived by offset, the Absolute Value will override the derived offset value.

To delete a Date Alias Instance from the displayed Calendar Instance using the Maintain Date Alias Instances form:

• Find the Date Alias Instance to be deleted
• Locate the cursor in the record to be deleted
• Delete record
• Save

Rules/Notes:

A Date Alias Instance cannot be deleted if it has been used to define a Date Alias Instance Offset.

Date Alias Instance Offset block

To create a Date Alias Instance Offset for the selected Date Alias Instance, using the Maintain Date Alias Instances form:

• Select the Offset Date Alias field in the Date Alias Instance Offset block
• From the list of values in the Offset Date Alias field select the Date Alias Instance from which the current Date Alias Instance will be offset
• Enter the Offset Duration in any combination of days, weeks, months and/or years. Values may be positive or negative. Notice that the Offset Alias Value (i.e. the date from which the new Date Alias Instance will be offset) is displayed
• Save

Rules/Notes:

A Date Alias Instance cannot be either a direct or indirect offset of itself.

The Offset Date Alias list of values displays an 'Alias Value' date only for those Date Alias Instances with an Absolute Value, not for those whose value derives from an offset.

If an Absolute Value for a Date Alias Instance already exists, the creation of an offset will not override it.

To modify a Date Alias Instance Offset using the Maintain Date Alias Instances form:

• Select the Date Alias Instance offset record to be modified
• Change the Offset Duration to the new values
• Save

Rules/Notes:

Only the Offset Duration can be modified. To specify an offset from a different Date Alias Instance the current Date Alias Instance offset must be deleted and a new offset created.

To delete a Date Alias Instance Offset using the Maintain Date Alias Instances form:

• Select the Date Alias Instance Offset record to be deleted
• Delete record
• Save

Rules/Notes:

When deleting an Date Alias Instance Offset attached to a Calendar Type with status ACTIVE, the Date Alias Instance must have an Absolute Value before deleting the offset.

Date Alias Instance Pair button

To create a Date Alias Instance pair, using the Maintain Date Alias Instances form:

• With the Date Alias Instance to be paired selected in CALF0511, select the Date Alias Instance Pair button. The Date Alias Instance Pair overlay is displayed
• Select the other half of the pair in the Related Date Alias field. Tabbing or saving causes the Related Alias Value to display
• Save