Shukla is the twenty-fourth nityayoga, and its name means bright, white, or pure, the same word names the waxing bright fortnight of the lunar month. It is one of the auspicious yogas, favourable for pure and bright undertakings, worship, and matters of clarity. Reckoned from the summed longitude of Sun and Moon divided into twenty-seven parts, it advances as the lights draw apart through the month. In the panchanga it contributes its favourable, luminous quality to the reckoning of an auspicious moment. These are the conventions of the calendar tradition, in which a benefic yoga such as Shukla is sought for good works; the astronomical basis remains the arithmetic of the two luminaries' combined longitude over the lunar month.
Shukla, bright or white, names not only this yoga and the waxing bright fortnight, Shukla paksha, of the lunar month, but also gives its name, in an entirely separate context, to a common Hindu surname found particularly among Brahmin communities of northern India, one of several caste-linked surnames, alongside Shastri, Pandit and others, that historically marked a family's traditional association with priestly or scholarly learning, an association the word's root sense of brightness or purity made a natural fit for.