HI @EnanBahadur,
Do you have a date table in your model? All good models needs a date table if you are calculating date difference. EDNA has the best Date table that @Melissa
Here is the link
Extended Date Table (Power Query M function) - Power Query / M Code Showcase - Enterprise DNA Forum
I downloaded your files and noticed that you really didn’t give it a try on the dax formulaes calculations. Where your issues are within the DAX formula?
There are plenty of examples in the courses\youtube
These are just some of the courses on EDNA
Chapgpt might help you dax too but you need check it too
thanks
Keith