According to the dharmaśāstras, every dvija (‘the twice-born,’ i.e., the brāhmaṇa, the kṣattriya and the vaiśya) has to follow a strictly regulated daily routine. Every item of it, even those pertaining to the physical needs of the body, should be considered and performed as a religious duty. Such an attitude is conducive to his spiritual welfare.
Such duties as are to be performed during the course of an ‘ahan’ or day, are called ‘āhnika.’ Day-time, for practical purposes, was extended for a short time before sunrise and after sunset. This period was usually divided into eight equal parts and different items of the daily routine were assigned to different periods of the day.
Principal matters discussed under āhnika are: bodhana and utthāna (getting up from the bed), śauca (bodily purity), dantadhāvana (brushing the teeth), snāna (bath), sandhyā (prayers to be offered at dawn), japa (repetition of mantras), tarpaṇa (libations to forefathers), pañcamahāyajñas (five daily sacrifices), homa (attending to the sacrificial fire), devapūjā (worship of God), bhojana (taking food), arthasañcayana (earning wealth), svādhyāya and pravacana (studying and teaching the Vedas), evening sandhyā, dāna (giving gifts) and nidrā (going to sleep).
Each one of these has been described in great detail in the smṛtis and digests often noting the alternatives or variations. The more important of these can be briefly described here.
Contemplating on God and holy beings is the first duty to be done, on waking up. Answering calls of nature should be done in consonance with the rules of health and sanitation. Bath should be taken in cold water, preferably in a river or a pond, repeating the Aghamarṣaṇa sūkta, the Puruṣa sūkta and other prescribed Vedic hymns. A householder is expected to bathe twice a day, once before sunrise and again before noon. While bathing, tarpaṇa (offering water ceremonially to gods, sages and manes) should also be done. Along with wearing fresh washed clothes after bath, putting the tilaka or caste mark (ūrdhva-puṇḍra, tiryakpuṇḍra, candana and so on) is also recommended. Then come the sandhyā ritual and Gāyatrī japa. This is followed by homa, offering libations of milk in the consecrated fire. Study of Vedic texts, feeding guests and animals, devoting time to the earning of wealth for maintain-ing the family are other items of daily routine.
For details, see under the respective title.
The word āhnika has been used as the name of the various chapters or sections of the Mahābhāṣya (the great commentary) by Patañjali on the grammatical sūtras of Pāṇini.