Polar Zmanim On The Antarctic Cruise

[jose34]

Between these sources, one will see addressed in regards to keeping shabbos:
(1) The preliminary question of whether the halakhic “day” requires a sunrise & sunset or a 24 hours (just about) period constitutes a day – this is largely based on proofs from Tanach, Gemaras, Midrashim (significantly a Pirkei D’Rav Elazar),
(2) Assuming a sunrise & sunset is required, is shabbos really every seven years!?!?,
(3) Assuming sunset & sunrise is not required to constitute a halakhic day (either on a d’orysa, or at least d’raban level [meaning, perhaps Shabbos on a d’orysa level is every seven years but to not “forget Shabbos” it should be kept on a rabbinic level every seven days – a similar, though not exact notion is noted when one is lost in a desert], what time does Shabbos begin or end:
(i) place where one left from [very ambiguous standard, what “place”],
(ii) lowest point of the sun is sunset, highest is sunrise (odd because lowest point is the sun’s general revolution (aka earth’s revolution) is chatzos, not sunset,
(iii) highest and lowest points of the sun are chatzos hayom and Layla, 12 hours in between each, six hours before highest point is sunrise, six hours later is sunset,
(iv) use the sunset/sunrise of the same longitude,
(v)  Just use Israel zmanim (Jerusalem?).

If so how do calculate? When do you start the seven years from?

[avromie7]

If so how do calculate? When do you start the seven years from?

Presumably year 1 since creation (5779 years ago) that's how we calculate leap years and shmitah. The bigger issue is calculating it in areas that have multiple days in a year meaning if one place has 2 days a year and you then move to a place that has 3, does it suddenly become shabbos if that's the day that place is up to?

[zh cohen]

Presumably year 1 since creation (5779 years ago) that's how we calculate leap years and shmitah. The bigger issue is calculating it in areas that have multiple days in a year meaning if one place has 2 days a year and you then move to a place that has 3, does it suddenly become shabbos if that's the day that place is up to?

Is that any different than the dateline question?

[Dan]

https://www.chabad.org/library/article_cdo/aid/4168250/jewish/How-to-Observe-Judaism-in-Outer-Space.htm

[Dan]

Indeed, transpolar flights are a major issue and many people don’t even realise. I am BEH working on an updated write-up about this.

Bump

[ExGingi]

Bump

+1

I have asked about this as it relates to Sefira since it seems to be a similar problem as crossing the dateline. There are also those that avoid crossing that line throughout the year (and let's not even get into the question of its location, and whether one should avoid getting into sfekos about it for non-necessities).

[jose34]

Bump

One of the main topics in R' Kuber's book.
Such as flights from NY to Japan.

[ExGingi]

One of the main topics in R' Kuber's book.
Such as flights from NY to Japan.

I guess using IST as a connection point for East-West flights is likely to skirt most of the issues.

[imayid2]

https://www.dansdeals.com/points-travel/trip-notes/guest-post-halachic-zmanim-polar-regions-kosher-antarctica-cruise/

In ‘The Great Zmanim Debate’ Rabbi Notice has an interesting perspective on polar Zmanim, based on the Gra: