In the Kotzk Blog.
Some excerpts:
Many are unaware just how many of our common practices today are taken from Chemdat Yamim. Sometimes these practices were known before and were simply publicised and encouraged by the book. Other times these practices appear to have been original innovations.
These include:
1) ‘LE DAVID HASHEM’:
-The widespread custom of reciting the Psalm LeDavid haShem Ori during the prayers (from the beginning of the month of Ellul until the end of the festive period.)
2) THE ‘TU BISHVAT SEDER’:
-The custom of celebrating Tu Bishvat the way many do today with a special Seder for eating fruits.[5]
In Chemdat Yamim it states: “It is a good custom to have many fruits on this day…as I instituted amongst my colleagues…and although it is not found in the writings of the Rav (Ari Zal), in my view it is a good rectification both in the nigleh (revealed) and nistar (hidden worlds).”
3) COUNTING THE ‘OMER’ AFTER THE SEDER:
-The custom (of some Chassidim) to count the first day of the Omer only after the Pesach Seder and Haggadah have been completed.[7]
4) ‘KE GAVNA’ INSERTION:
-The custom, as included in many siddurim today, to recite the ‘Ke Gavna’ (passages from the Zohar) on Friday evenings after Lecha Dodi.
5) ‘RIBBONO SHEL OLAM’ PRAYER:
-The custom to recite the Ribbono Shel Olam on Yom Tov when the Torah is taken out. The verse ‘venacha alav ruach haShem (may G-d’s spirit rest on him)’ is said to have been a reference to Shabbetai Tzvi.
6) TASHLICH PRAYER:
-Some aspects of the Tashlich ceremony on Rosh Hashana are also attributed to Chemdat Yamim.
Follow the omitted footnotes in the original here…