CALCULATING HINDU RELIGIOUS AND FESTIVAL DATES
The Priest’s Council of the South African Hindu Maha Sabha (SAHMS), representing linguistic and ideological diversity in the Hindu sector, annually declares festival dates for the South African Hindu public. Often confusion arises due to time zone differences with India. Information on Google pertains primarily to India. The Hindu calendar is called the panchang or panchangam and scriptural principles to calculate festival dates can be traced to the Rig-Veda. As far as possible, attempts are made to reach consensus on these principles, thereby eliminating any difference of interpretation and avoiding public confusion.
The Priests’ Council
The Priests’ Council of the South African Maha Sabha brings together Hindi, Tamil, Telugu and Gujarati Priests to reach consensus on Hindu festival dates (including Diwali). It includes representatives from the Gurumar Sangam of South Africa (Tamil), Andhra Maha Sabha of South Africa (Telugu), Shree Sanathan Dharma of Sabha South Africa (Hindi) and World Hindu Priests Organisation (Gujarati and overseas Priests). In addition, there are other Priests who, by virtue of their specialised knowledge of the calculation of Hindu festival dates, also serve on the Council. The South African Hindu Maha Sabha is an all-embracing federal organisation driven by its affiliates. In the true spirit of Hindu diversity, the South African Hindu Maha Sabha respects the diverse linguistic perspectives on festival dates. Once again, as far as possible the aim is to reach consensus and avoid confusion.
The Hindu Calendar
The Hindu calendar is based on the revolution of the earth around the sun and the different phases of the moon and is, therefore, lunisolar. Thus, a solar year is divided into 12 lunar months. A lunar month refers to the time required for the moon to orbit around the earth and pass through its complete cycle of phases. The Hindu calendar system uses a multi-dimensional method of structuring time, combining information about lunar days, solar days, lunar months, solar months, the movements of the Sun and the Moon and stellar constellations, and other astronomically defined periods. This makes the Hindu calendar vastly more complex than the western one, which only considers solar days and solar years. Therefore, it is not advisable to interpret Hindu festival dates within the framework of the western calendar. Hindu festival dates are based on tithis.
Tithis at Sunrise
According to Bhujle and Vahia in the Annals of Bhandarkar Oriental Research Institute (2006, p. 1), “tithis are the dates of Lunar Calendar”. They further state that “the tithi is the time taken by the Moon in increasing its distance from the Sun by 12 degrees. The complete revolution of the Moon (29.5 days) occupies 30 tithis for 360 degrees. Since the motions of the Sun and Moon are always varying in speed, the length of a tithi constantly alters (Bhujle and Vahia, 2006, p. 2).
Bhujle and Vahia (2006, p. 4) also maintain that “from the point of view of a calendar, a tithi begins on one day and ends on the following day. However, the length of the tithi alters quite often since the apparent motions are not linear. The length of a tithi may begin and end within the limits of same solar day. On other occasions, the Moon may remain in the same tithi for as many as two days, occupying the whole of one and parts of the other solar day.
There is an important difference between the Hindu calendar and the western calendar. The English date and the day (Sunday, Monday, Tuesday, etc.) change at midnight, whereas the Hindu date or tithi (the festival falls into) does not change at midnight. Hindu day changes at sunrise.
The usual rule to observe the festival is whenever that tithi prevails at sunrise. But for certain festivals, rules change, especially Ganesh Chaturthi, Krishna Ashtami, and Mahashivaratri. For example, Ganesha Chaturthi has to be observed when the Chaturthi tithi is observed during the 8th/15 part of the dinmana or the 3/5th part of the dinmana. The dinmana is the difference between the local sunset and the sunrise on the same day. If Chaturthi is not prevailing during that period, take the second day.
All festivals and fasting days in the Hindu calendar are location-based, i.e., geo-location is considered while calculating the dates of Hindu events. One interesting fact of location based Hindu events is that the event might be observed one day ahead in South African cities and one day later in Indian cities. This is opposite to the time zone rule, confusing for those who calculate Hindu events based on time zone shifts. As per time zone shift, if the Mahashivaratri date for New Delhi, India, falls on 1 March 2022, then the date as per Durban, South African clock is behind by 3½ hours that of New Delhi. In fact, as per Mahashivaratri observance rules, the actual date for Durban, South Africa, is 28 February 2022, i.e., one day before New Delhi.
The Panchang contains two types of calculations. One is based on local coordinates like longitude and latitude, and the other is based on geocentric astronomical phenomena. The first calculation is always done for each place on the earth. The earth is not flat, and the horizon will vary from place to place. Hence, the first set of calculations may vary from place to place. These varying calculations are based on local parameters such as sunrise, sunset, and moonrise. The second set of calculations is based on some astronomical phenomenon from the centre of the earth (geocentric).
According to Pundit Mahesh Shastri and Dr. Ramachandra Joisa, the planetary positions are first calculated from the centre of the sun (heliocentric), then spherical trigonometry, they are converted to the centre of the earth (geocentric). These are calculated based on Universal Time (UT). These are astronomical phenomenon. It happens instantly at the same moment on the earth, and hence thithis will end at the same time worldwide. But we have to convert them to the local standard time. The time difference between India and South Africa is 3 hours and 30 minutes. The planets do not remain static during that time. They keep on moving, and hence we will have a new tithi at the same time and date in different parts of the world. However, if you add and subtract the time difference from the Indian calendar, you will arrive when that tithi changes in your locality.
Calculating Hindu religious and festival dates is challenging, requires accuracy and scientific precision, and it is a responsibility which the South Africa Hindu Maha Sabha does not take lightly. The Priests’ Council of comprises of a team of senior Hindu priests who represent the ideological, cultural and linguistic diversity in our country. Draft religious dates are released for public comment and input, before final approval. Sometimes there are differences in in the ‘North and South Indian’ dates, and this is accommodated