[Avodah] 3 days a year

[Liron Kopinsky]

Hi All,
I had a thought this morning about Hoshana Rabba, Erev YK and Erev
Pesach being the 3 days a year that are semi-Yom Tov.

HR: Yom Tov Davening (for the most part)
Erev YK: Seudat Yom Tov
Erev Pesach: Issur Melacha (to some)

It seems to me that these 3 days combined make up one full Yom Tov day.

Has anyone heard anything to this effect before?

I heard an idea tying Erev YK, HR and Purim together where there is a
minhag to eat Kreplach since it is a day of simcha but not an actual
Yom Tov, so we hide the meat but this is obviously not possible on
Erev Pesach.

Thanks,
~Liron