Hi, I need help. I'm creating a calendar, based on events at our farm, which are on different dates.

As always, mathetes​ is right that we are really guessing here and attaching a sample sheet or hosting one online (e.g. onedrive or google drive) would be a huge help.  Based on your description I'm taking a guess and agree again with mathetes that your data format is the problem.  So my guess is you have a sheet something like this:

which is the problem so I created a helper sheet I called 'Dates' and converted the above to a more functional format with a date column followed by the event names:

by the way the formula I used was:

=LET(in,Events!B1:.Z99,c,COLUMNS(in),
list,REDUCE(HSTACK("Date","Event"),SEQUENCE(c),LAMBDA(p,q,VSTACK(p,EXPAND(DROP(CHOOSECOLS(in,q),1),,2,INDEX(in,1,q))))),
VSTACK(TAKE(list,1),SORT(DROP(FILTER(list,TAKE(list,,1)<>0),1))))

then i created a calendar like this:

where the box under each date used a formula like this formula which was in B7 (under the day 6 box):

=TEXTJOIN(CHAR(10),1,FILTER(TAKE(Dates!$A$1#,,-1),TAKE(Dates!$A$1#,,1)=B6,""))

I will try to attach the sample file separately