Is there a practice or obligation to observe two days of Yom Kippur (like two days of Yom Tov for Diaspora)?

Yom KippurAfter YK

Synopsis

The Rema records that some pious people observed two days of Yom Kippur. This is strongly discouraged by all authorities due to the life-threatening danger of a 48-hour fast. It requires formal vow annulment to stop.

Early Acharonim
Late Acharonim
Lenient
Strict
Lesser cited
Major authority

Discussion

Discussion coming soon.

The Daily Law

One question. Every opinion. Every morning.

A new halakhic question and the full spectrum of rabbinic thought, delivered daily.