Open Source Spreadsheet help

I'm trying to create a spreadsheet in which I can place a list of name and set them to either 1 month member, 3 month member or lifetime member what I want is the cell that 1 month members names are in to turn red after that specific member has been on the list for 28 days and for the 3 months members names to do the same but after 84 days, but I've go no idea where to start.

(I'm currently using open office)

 

I think what you're looking for could easily be done with conditional formatting, linked to a date (of joining) field?

 

Can't explain so how's this?

Link https://drive.google.com/file/d/16edS2J0pJVphshoNcSjVSIaFgyLVFi8G/view?usp=sharing

Let me know when done so I can remove the file

 

Did you manage to get this sorted?

 

yes thank you