Excel spreadsheet - how to calculate the 28th day

Hi, I am trying to make a workload tracker.

For context, I manually make a 3 monthly checklist where i calculate the next 3 due dates and type up it myself every month which is very time consuming.
i have a hundred over a 100 patients and they have a due date. so accross the month they are spread out into 4 weeks. so week 1 has about 15 patients due accross the week for example and week 2 has another 15 or 16 patients due etc. and then after the 4th week, we start from week 1 patients again.

I want to put it into a excel spreadsheet so the dates are calculated for me.

For example, lets say the first due date for TOM is 13/02/2024. so now i need the due dates for next 2 months fo TOM as well, which is the next 28th day. so the next 2 due dates would be 12/03/2024 and 09/04/2024.
so the next due date is after 28 days.

so lets say in the spreadsheet, the date in column B2 is 12/03/2024,
i want the spreadsheet to calculate the next 28th day and set the date in E2 to 12/03/2024 and the date in H2 to 09/04/2024.

what formulas will i use to get excel to calculate the due dates for me?

would appreciate any help urgently. thank you

Have you seen this?

https://support.microsoft.com/en-gb/office/add-or-subtract-dates-b83768f5-f695-4311-98b1-757345f7e926

I don't have excel in front of me but try:

If your date is in cell E2, and you want the next date in H2 to be 28 days afterwards, then in cell H2 enter:

=DATE(YEAR(E2),MONTH(E2),DAY(E2)+28)