[Avodah] Yoma Arichta - RH in EY

[rabbirichwolpoe at gmail.com]

What is the earliest source for observing two days of RH even in EY?

My Mishnah Brurah has the following info

SA 601:2 even in EY one makes 2 days

Be'er Hagolah 3: Rif first pereq of Beitza, Rambam...

MB 3: ...even in the time of the Miqdash somedays they needed to make
2 days

Shaar haTziyyun 2:
Darchei Moshe 604 in the name of the Maharil.

Any evidence from Bavli, Yerushalmi or Tosefta? Any Gaonic sources?

Shana Tova
RRW
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