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Pulling weekday vs weekend chagim
I'm looking to calculate for each chag, what the probability is that the full-day of chag will fall on a workday (Monday - Friday) and what is the probability of a weekend (Saturday-Sunday) over the 19 year cycle.
I would be as happy to have a way to look at probability by day of the week.
I prompted ChatGPT and other AI bots, but they all got the dates totally wrong.
Is there a way to easily pull this from hebcal?
Answer
Hi, thanks for your message. This is pretty easy to calculate using the Hebcal command-line interface. Here's the general idea:
$ hebcal --chag-only -w | egrep -v "(Erev|CH''M|Hoshana)"
4/23/2024 Tue, Pesach I
4/24/2024 Wed, Pesach II
4/29/2024 Mon, Pesach VII
4/30/2024 Tue, Pesach VIII
6/12/2024 Wed, Shavuot I
6/13/2024 Thu, Shavuot II
10/3/2024 Thu, Rosh Hashana 5785
10/4/2024 Fri, Rosh Hashana II
10/12/2024 Sat, Yom Kippur
10/17/2024 Thu, Sukkot I
10/18/2024 Fri, Sukkot II
10/24/2024 Thu, Shmini Atzeret
10/25/2024 Fri, Simchat Torah
Now we need to just count how many times each holiday occurs on Sat or Sun versus another day
$ hebcal --chag-only -w --years 100 2000 | egrep -v "(Erev|CH''M|Hoshana)" | grep "Yom Kippur" | egrep "(Sat|Sun)," | wc -l
32
Here is a summary:
- Rosh Hashana: 58 / 200 chag days on Saturday or Sunday
- Yom Kippur: 32 / 100 days on Saturday or Sunday
- Sukkot: 58 / 200 chag days on Saturday or Sunday
- Pesach: 117 / 400 chag days on Saturday or Sunday
- Shavuot: 56 / 200 chag days on Saturday or Sunday
Note that we used a 100 year window to approximate. Note that has little to do with the 19-year cycle and more to do with the interaction between the Hebrew and Gregorian calendars. See the Jewish-Gregorian calendar correspondence cycle for more details on that. A calculation can be done with 1000 years, yielding similar results.
A similar calculation could be done for Israel if you add the -i flag, and adjust for the Israeli weekend (Friday + Saturday).
Customer support service by UserEcho
Hi, thanks for your message. This is pretty easy to calculate using the Hebcal command-line interface. Here's the general idea:
$ hebcal --chag-only -w | egrep -v "(Erev|CH''M|Hoshana)"
4/23/2024 Tue, Pesach I
4/24/2024 Wed, Pesach II
4/29/2024 Mon, Pesach VII
4/30/2024 Tue, Pesach VIII
6/12/2024 Wed, Shavuot I
6/13/2024 Thu, Shavuot II
10/3/2024 Thu, Rosh Hashana 5785
10/4/2024 Fri, Rosh Hashana II
10/12/2024 Sat, Yom Kippur
10/17/2024 Thu, Sukkot I
10/18/2024 Fri, Sukkot II
10/24/2024 Thu, Shmini Atzeret
10/25/2024 Fri, Simchat Torah
Now we need to just count how many times each holiday occurs on Sat or Sun versus another day
$ hebcal --chag-only -w --years 100 2000 | egrep -v "(Erev|CH''M|Hoshana)" | grep "Yom Kippur" | egrep "(Sat|Sun)," | wc -l
32
Here is a summary:
Note that we used a 100 year window to approximate. Note that has little to do with the 19-year cycle and more to do with the interaction between the Hebrew and Gregorian calendars. See the Jewish-Gregorian calendar correspondence cycle for more details on that. A calculation can be done with 1000 years, yielding similar results.
A similar calculation could be done for Israel if you add the -i flag, and adjust for the Israeli weekend (Friday + Saturday).