If a wanderer knows the number of days since he departed (e.g., today is the fourth day since he left) but not which day of the week he departed, when may he freely perform labor?
Synopsis
When the wanderer knows how many days he has traveled but not the day of departure, he may freely work on the 8th, 15th, 22nd days of travel (and so on in multiples of seven from the 8th), since he certainly did not depart on Shabbat. The Mishnah Berurah adds that he may not work freely on day 9 (since he might have departed on erev Shabbat).
More in Tying and Untying on Shabbat
If a person lost track of which day is Shabbat while wandering in the desert, from which day does he begin counting his seven-day cycle?
3 opinions
How does a desert wanderer who lost track of Shabbat fulfill the obligation of Kiddush and Havdalah on his designated seventh day?
2 opinions
May a desert wanderer who has food/provisions perform labor on any of the seven days (including days that might not be Shabbat)?
5 opinions
When labor is permitted for sustenance (after provisions are exhausted), how much may the wanderer earn — may he work extra on one day to avoid labor on subsequent days?
4 opinions
May the desert wanderer walk (travel) on any day of the week, including his designated seventh day?
4 opinions
On the designated seventh day, may the wanderer perform other rabbinic prohibitions (shevutim d'rabbanan) besides walking?
4 opinions
Is a desert wanderer who lost track of Shabbat obligated to wear tefillin on his designated seventh day?
1 opinions
Does the same 'lost Shabbat' framework apply to someone who lost track of Yom Tov (e.g., does not know if today is a chag)?
2 opinions
Related from other topics
During which prayer services is Birkat Kohanim (Duchanin) performed?
Birkat Kohanim Restrictions
On which fast days is the Neilah prayer recited (relevant to determining when Birkat Kohanim is performed at Mincha)?
Birkat Kohanim Restrictions
What is the minimum number of verses each individual reader must read, and which reader is considered praiseworthy for reading more?
Maftir Aliyah Laws
Does one fulfill the shnayim mikra obligation if they read 'Atarot v'Divon' (and similar proper nouns) only twice in Hebrew without any Targum, since no standard Targum exists for these words?
Bandaging and Wound Care on Shabbat
When a person eats in one place and sleeps in another (e.g., brothers who eat in their father's house but sleep in their own), which location determines where they create an eruv restriction?
Eruv Requirements for Courtyards
What are the obligations of heirs who inherit a home in which the deceased owner failed to perform bedikat chametz before Pesach?
Chametz After Pesach
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.