Calculating yearly/ monthly days between a

Andrei_Fleancu , Based on what I got, Refer

Between Dates - Dates between
Measure way
Power BI Dax Measure- Allocate data between Range: https://youtu.be/O653vwLTUzM
https://community.powerbi.com/t5/Community-Blog/How-to-divide-distribute-values-between-start-date-or-end-date/ba-p/1503785

Tables way
https://amitchandak.mediumcom/dax-get-all-dates-between-the-start-and-end-date-8f3dac4ff90b
https://amitchandak.medium.com/power-query-get-all-dates-between-the-start-and-end-date-9ad6a84cf5f2

If this does not help
Can you share sample data and sample output in table format? Or a sample pbix after removing sensitive data.