Reasons for differences in dates on Hindu calendar

Dear Editor,
I think the Hindu public needs to be informed of the reasons for the differences in dates on the Hindu calendar. Specifically, why all the dates on Dharmic Sabha’s calendar are exactly one day after the dates on the calendars of all other Hindu organisations?
At a meeting held at Dharmic Sabha Kendra on Monday 22 August, 2016, and attended by Pandits of Viraat Sabha, Pandits’ Sabha of Region 3, Pandits’ Council and Gandhi Youth, the matter was discussed.
In its explanation on the system and methods used in arriving at its Dates, Dharmic Sabha revealed that it has been using the time given in the Panchang (Hindu Astrological Chart) as the ‘Starting’ Time. The Pandits of all other organisations present vehemently disagreed; they asserted that the Time is the ‘Ending’ Time, and not the Starting Time.
It should be mentioned that this is supposed to be public knowledge, known especially by all students of Astrology. Also, the Astrological Charts, in their guidelines, mention that all times are given as the ‘Ending’ Time.
The use of these times as the starting position of each Lunar Day (Tithi) has resulted in all Dharmic Sabha’s dates being one day later than the dates on the Charts, and as well the calendars of the other organisations.
Thus, when the Full Moon ended at 5:26 am on 18 August, Dharmic Sabha treated it as having started then, thereby celebrating Raksha Bandhan one day after. Again, Ashtami (8th lunar day), according to the Panchangas, started on the 24 August and ended at 10:40 am on the 25th.
Dharmic Sabha is using 10:40 am on 25th as the starting time of Ashtami, thus celebrating Janam Ashtami on the 25th.
Similarly, for Diwali. Amaavasya (Diwali) ends at 1:37 pm on the 30th of October. Dharmic Sabha is treating 1:37 pm on the 30th as the starting time of Diwali. So their date for Diwali is the 30th instead of the 29th.
This is a fatal error which has resulted in all their dates occurring one day later. It should be mentioned that Dharmic Sabha’s dates do not agree with those in the Panchangas.

Yours truly,
Pt R Balbadar
Sanskrit and Vaidic
Theology Dip