Dates Macro. Calculating date based on current date and input date

I am currently working on a project wherein i require Cell A1 to have a user inputted date say todays date as start date of April 30, 2017. In cell B1, I want the macro to auto generate a date that is 30 days from today including the weekends.

In Cell C1 i want the macro to enter 60 days from today and in cell D1 to enter 90 days from todays inputted date. The macro should update all three fields once the date is updated.

This trend should follow in Column A, Column B and Column C, Column D, Column E and Column F everytime the date changes in Column A,

Cell E1 must have a date that is 2 weeks from the date in A1
Cell F1 must a date that is have 3 weeks from the date in A1.

Part 2

If today's date is 4 days before the date in B1, C1, D1 E1.F1 Then excel will change the cell color to Blue
If todays date is 2 days before the date in B1, C1 D1, E1, F1 Then excel will change the cell color to Yellow
If todays date in 1 day before the date in B1, C1, D1, E1 F1 then excel will change the cell color to RED.

ANy help is greatly appreciated.