What follows is my provisional translation (in other words, not official or authorized; see here for more) of a passage from a Tablet of ‘Abdu’l-Bahá, the original text of which is published in Amr va Khalq, vol. 4, p. 12.
Work is prohibited on three days of the Riḍván festival: the First, the Ninth, and the Twelfth. So too with the anniversaries of the Birth of the Báb and the Birth of Bahá’u’lláh, as well as the festival of Naw-Rúz and the anniversary of the Declaration [of the Báb]. My meaning is that it is forbidden to work on the Holy Days. In the case of Riḍván, this applieth to three days—and if, in [the period of] Naw-Rúz,* work is suspended on a few more days than just the one, this practice would be preferable, but it is not a binding obligation.
* In Iranian culture, Naw-Rúz is not limited to the day of the vernal equinox; rather, it is a period that continues for the next 13 days.
A typescript of the original Persian text of this passage appears below.