[ui5-special-date]: value does not respect format-pattern of ui5-calendar

[floa93]

Bug Description

If a ui5-special-date is given with a value(e.g. value="20240528" ) in the format-pattern of the parent ui5-calendar(e.g. format-pattern="yyyyMMdd" ) an javascript error occurs and the calendar doesn't render.

This calendar typescript code uses the Javascript date function

ui5-webcomponents/packages/main/src/Calendar.ts

Line 345 in 648717a

const dateFromValue = new Date(date.value);

, which does not respect the format-pattern like done in

ui5-webcomponents/packages/main/src/Calendar.ts

Line 325 in 648717a

const date = this.getFormat().parse(dateString);

to check if this is a valid special date.

Affected Component

ui5-special-date

Expected Behaviour

The calendar special date should be usable with the custom format-pattern given

Isolated Example

No response

Steps to Reproduce

<ui5-calendar format-pattern="yyyyMMdd" hide-week-numbers min-date="20240501" max-date="20241224">
    <ui5-special-date slot="specialDates" ui5-special-date value="20240528" type="Type01"></ui5-special-date>
</ui5-calendar>

Workaround: use a valid new date() format like yyyy-MM-dd

<ui5-calendar format-pattern="yyyy-MM-dd" hide-week-numbers min-date="2024-05-01" max-date="2024-12-24">
    <ui5-special-date slot="specialDates" ui5-special-date value="2024-05-28" type="Type01"></ui5-special-date>
</ui5-calendar>

### Log Output, Stack Trace or Screenshots

CalendarDate.js:143 Uncaught (in promise) Error: Date parameter must be a JavaScript Date object: [Invalid Date].
at CalendarDate.fromLocalJSDate (CalendarDate.js:143:1)
at Calendar.js:186:46
at Array.forEach ()
at get _specialCalendarDates (Calendar.js:181:1)
at Calendar.block0 (CalendarTemplate.lit.js:3:3983)
at executeTemplate (executeTemplate.js:12:1)
at Calendar.render (UI5Element.js:104:31)
at updateShadowRoot (updateShadowRoot.js:20:1)
at Calendar._render (UI5Element.js:580:29)
at renderImmediately (Render.js:31:1)

### Priority

None

### UI5 Web Components Version

1.24.3

### Browser

Chrome, Edge, Firefox

### Operating System

Windows

### Additional Context

Its not a big issue since an easy workaround is to just use a valid new date() format like yyyy-MM-dd

```

Organization

SAP

Declaration

• I’m not disclosing any internal or sensitive information.

[plamenivanov91]

Hello @SAP/ui5-webcomponents-topic-b,

It seems value="20240528" is not recognized as valid date in our code.

Is this expected behavior ?

Also, the issue is reproducible in the main branch.

Regards,
Plamen Ivanov