Ah, just remembered I already reported this last year in 2022, but it wasn't fix, this was the answer given by a TH worker, who did not code this addon:
It's coded to be enabled all week - to be honest I'm not sure why that is as I didn't build it but that's how it's currently set up.”
which is the reason I had to put it down manually.
So if anybody's wondering, it's a known issue, little mistake on creation but might not get fixed. I totally forgot I asked about it last year myself... memory error on my side.
Edit... for whom is interested, I fixed both Eastern and Thanksgiving. Seems Holidays was giving the holidays (when people have free days) so not only the celebration days itself (at least for Easter and Thanksgiving anyway). Hence Easter a week and Thanksgiving 3 days.
I only know a very little php by the way.
In HolidayCalc.php I had a look and for easter under " public static function easter(Holiday $holiday)" I changed the last line with "addweek" to:
$end = (clone($start))->addDays(1)->endOfDay();
There is also this code for Eastern below this one, but I have no clue as to why that is there or why it's needed (as said, know very little php).
Code:
public static function lent(Holiday $holiday)
{
$time = self::getTime();
$end = (Carbon::createFromTimestamp(easter_date($time->year)))->subDay();
$start = (clone($end))->subDays(44)->startOfDay();
$end->subDay()->endOfDay();
return $time->between($start, $end);
}
Anyway, a little higher in that file, for Thanksgiving I changed the line with "addDays(3)" to:
$end = (clone($start))->endOfDay();
so now it's only 1 day as Thanksgiving is in fact only 1 day if I'm not mistaken.