Conventions of Indian calendars

[Frank Conlon]

Friends:

I am attempting to recapture something which I once learned, but have 
managed to forget concerning systems of dating in India.  I think I 
recall that in the definition of months, in north India and south India 
(roughly) there was a difference as to whether the month began with the 
bright (shukla) half or the dark (krishna) half.

Would some of you be so kind as to refresh my memory as to whether

(1) I am correct in my recollection?
(2) Which region has shukla or krishna first?
(3) Can we identify a sort of calendrical frontier where practice changes?
(4) Does this really mean that if we use a date of shukla 10th of one 
month that in another part of India that day would be recorded as krishna 
of the adjacent month?

My own perspective on time as my seniority grows is being reduced to one 
principle--"the farther south you go, the later it gets."

Thanks

Frank Conlon