feat(local-notifications): add start date to cron like scheduler

[F0079]

Description

This feature provides the possibility to add a start date to a cron job like scheduler. To make use of a start date, the at property has to be defined in addition to the on property of the Schedule entity. If both are present, then the cron like scheduler is postponed to the given start date.

Current Schedule definition: https://capacitorjs.com/docs/apis/local-notifications#schedule-1

Change Type

• Fix
• Feature
• Refactor
• Breaking Change
• Documentation
• Other (CI, chores, etc.)

Rationale / Problems Fixed

This feature supports the use case "Schedule a notification starting next week on a daily base."

This kind of functionality is already described by issue #131. Instead of using the every property, this feature request makes use of the cron like scheduler configuration because it is more powerful.

Tests or Reproductions

A test case "Schedule every minute, starting in 5 minutes" will be added to the test app by pull request #787 in the capacitor-testapp repository.

Platforms Affected

• Android
• iOS
• Web

Notes / Comments

Associated Pull Requests

• Pull Request capacitor-testapp: feat(local-notifications): add test case for recurrent notifications with a start date capacitor-testapp#787
• Pull Request capacitor-docs: feat(local-notifications): add documentation about cron like schedule with start date capacitor-docs#561