Hari Om! This is the post made by well know astrologer-researcher Narasimha Rao. I hope it will be useful :)
"There is a little confusion in India on whether the new year starts on 2017 March 28 or 29. If you live in US or Europe, there is no confusion - Chaitra Sukla Pratipada started on Monday night and ends on Tuesday night. So it is clearly Tuesday.
In India, Chaitra Sukla Pratipada starts on Monday after sunrise and ends before the sunrise on Tuesday. Again, as per shastras, it is on Tuesday.
However, some people do not use Drik siddhanta and erroneously stick to outdated formulas for computing planets. They get the end of Pratipada a little after sunrise on Wednesday.
Ancients did curve fitting on observations of their time and gave simple formulas for easy computation without constant observation. These formulas were meant to be refined from era to era, to match observations within some precision. However, some scholars of Kali yuga decided to just use them without refinement for ever, thus considerably deviating from observations!
Even in that case, Pratipada does not last long enough after sunrise on Wednesday. So, as per the minimum time given by shastras, Wednesday does not qualify and it is still Tuesday. But they ignore the minimum time dictum and claim that Wednesday is the new year day.
They are using wrong planetary calculations and also ignoring the minimum time dictum. Unfortunately, two wrongs don't make a right in this case. :-)
In any case, I do think this new year definition based on Chaitra Sukla Pratipada is a relatively modern definition. Upanishads speak of a different lunar new year. Even today, there are many different new lunar years defined in different parts of the world. People take new Moon and full Moon of various months as the start of lunar new year."
Happy Yugadi, Ugadi, Samvatsaradi, Gudi Padwa or lunar new year, to those who celebrate it today/tomorrow).:)