Dynamic Timeline generation

Hi guys,

I am trying to create a worksheet which will eventually help me build a timeline / gantt chart.
Since, I am still learning excel and do not know Macros/VBA. I am still unsure if what I want can be done without the "advanced" skills.

I have currently broken down the issues in small parts and I am currently at stage one, where I am trying to get a list of dates to be automatically generated according to the start and end date mentioned. The dates are to be automatically generated in the cells below in an increment of an year.
I am aware that 'EDATE' And 'IF' can be used for such a task.

However, once the dates are generated I would be manually entering some dates under the cells. All the dates are to be automatically sorted from the oldest to newest. The current formula doesn't not have a limiter as to the end date, and manually sorting by date messes the whole thing.

I have attached my current worksheet (very basic).

Outcome trying to achieve:

- Auto-generation of dates and their corresponding 'SP' in the next column.
- Auto sort of date: Oldest to Newest, after manual entry of date in the rows below
- Calculation of gap in months (DATEDIF), between "Manual entry / non SP event" and the 'SP' it happened in.
(For Example Event A occurs in SP1 and the gap in month would be 1)



Thank you