Schedule - Show Preview function should calculate dates in exactly the same way as the Daily Plan

Current Situation

• General Notes: The calculation of schedule start time periods generally follows a two-step process:
  • Step 1 Preliminary calculation of the matching dates based on working calendars and schedule restrictions.
  • Step 2 Calculation of the start time periods for the dates obtained in Step 1, with additional consideration for non-working calendars, as non-working days can be treated differently, including:
    • suppress execution (default)
    • ignore non-working day
    • before non-working day
    • after non-working day
• Daily Plan and Schedule Show Preview
  • Step 1 Note: both use a common component, FrequencyResolver.
    • Daily Plan A new instance of FrequencyResolver is created for each day, using a 1-Day date range.
    • Schedule Show Preview A single instance is created for the full date range (Year or Month).
    • FrequencyResolver Depending on the chosen date range, the FrequencyResolver performs calculations differently, for example:
      • with a year range, it is easier to calculate the workday number of a specific date since previous days have already been computed.
      • with daily calculations, the component must calculate backwards or forwards for each task in order to evaluate missing days.
  • Step 2 Note: This step is not normalized, and start times will be calculated based on the specific implementation.
    • Daily Plan Calculation for a single day.
    • Schedule Show Preview Calculation for a range of dates.
• Conclusion
  • The different ways of handling and parameterizing the process can cause discrepancies between the results from Daily Plan and Schedule Show Preview.

Desired Behaviour

• The Schedule Show Preview function should mirror Daily Plan's functionality to minimize discrepancies between the Preview and the generated Schedule start time periods.

Maintaner Notes

• Schedule Show Preview
  • Step 1, Step 2 Operates now like Daily Plan d.h. using 1-Day date range
  • Note Step 2 The implementations for Daily Plan and Schedule Show Preview are still not standardized, but Schedule Show Preview has been adjusted to match Step 2 of Daily Plan.

Test Instructions

• Note: The tests should focus on the Schedule Show Preview (Calendar Show Preview and Daily Plan remain unaffected).
• Test various Schedules with different configurations (e.g., Weekdays, Every, with/without the non-working calendar etc.).
• Validate that the correct days are displayed across timeframes (e.g., current year, next year).
• Performance Tests Note: The preview now performs ~365 calculations internally instead of a single yearly calculation, increasing workload.
  • Expected result: Response times must remain unchanged, with immediate display of preview dates.