Time (secs in a year)

[Fred McWilliams <fredmcw@MIT.EDU>]

First of all, I believe in being as accurate as possible.  Yes, the largest 

error will be in the half-life used, however, in most cases the half lifes 

are stated with associated errors.  This is simply because its a 

probability distribution function and not a constant as is time.



As long as one states the assumption and the source used in the 

calculation, then whether its 365 or 365.25 does not matter, since anyone 

should be able to calculate the value they desire.



I have found that most use s,m,h,d for half lifes less than one year and 

for half-lifes greater than 4 years, 365.25 and for all other cases 365 days.



A quick search on NISTs Web site produced the following



http://physics.nist.gov/Pubs/SP811/appenB8.html#Y



http://physics.nist.gov/Pubs/SP811/appenB9.html#TIME



Regardless state the assumptions and references and most anyone can then 

follow the work.



Granted..... this is my opinion.





Fred McWilliams

MIT



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