How can I make a complex ifelse algorithm which comprehend dates and time?

Question

I have got a data-management problem. I have a database where "EDSS.1","EDSS.2",... represent a numeric variable, scaled from 0 to 10 (0.5 scale), where higher number stand for higher disability. For each EDSS variable, I have a "VISITDATE.1", "VISITDATE.2",...

EDSS

VISITDATE

Now I am interested in assessing the CONFIRMED DISABILITY PROGRESSION (CDP), which is an increased i 1 poin on the EDSS. To make things more difficult, this increment need to be confirmed in the subsequent visit (e.g. EDSS.3) which has to be >= 6 months (which is, VISITDATE.3 - VISITDATE.2 > 6 months.

To do so, I am creating a nested ifelse statement, as showed below.

prova <- prova %>% mutate(
  CDP = ifelse(EDSS.2 > EDSS.1 & EDSS.3>=EDSS.2 & difftime(VISITDATE.3,VISITDATE.2, 
                                                           units = "weeks") > 48,
               print(ymd(VISITDATE.2)),0))

However, I am facing the following main problems:

1. How can I print the VISIT.DATE of my interest instead of 1 or 0?
2. How can I shift my code to the EDSS.2,EDSS.3, and so on? I am interested in finding all the confirmed disability progressions (CDPs).

Many thanks to everyone who find the time to answer me.