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To:	MRGATE::"ARISIA::EVERHART"
Subj:	Re: Month


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Date: 21 Feb 89 15:30:02 GMT
From: munnari!vuwcomp!wnv!gpwd!gpwrmdh@uunet.uu.net  (Martin D. Hunt)
Organization: Government Printing Office, Wellington, New Zealand
Subject: Re: Month
Message-Id: <295@gp.govt.nz>
References: <246@gp.govt.nz>, <603498985.0.TOM@MARS>
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In article <603498985.0.TOM@MARS>, TOM%Irving@VX1.GBA.NYU.EDU (Tom C Crowley) writes:
> 	Date: 27 Jan 89 05:30:24 GMT
> 	From: munnari!vuwcomp!wnv!gpwd!gpwrmdh@uunet.uu.net (Martin D. Hunt)
> 	Organization: Government Printing Office, Wellington, New Zealand
> 	Subject: Re: Month
> 	
> 	In article <8901221116.AA12223@ucbvax.Berkeley.EDU>, Brian.T.Carcich@CUSPIF.TN.CORNELL.EDU writes:
> 	>>     
> 	>>Just a quick question - is there ANY easy, lexical-like way to get the
> 	>>next month from the current? 
> 	>>     
> 	> 
> 	> How about this:
> 	> 
> 	> $ write sys$output f$cvtime(f$extract(2,5,f$time())+"+31-","absolute","month")
> 	> or 
> 	> $ nextmon=         f$cvtime(f$extract(2,5,f$time())+"+31-","absolute","month")
> 	> 
> 	
> 	Yuk! There is a simple call which only needs one lexical function call:
> 	
> 	$ nextmon = f$cvtime ("+31-", "absolute", "month")
> 	
> 	I can't understand why the above example wastes time mucking around with
> 	f$extract, when f$cvtime does it all for you anyway.
> 	
> 	Martin D. Hunt
> 	Government Printing Office
> 	Wellington
> 	New Zealand
> 	
> Wrong.  Think what would happen with your solution on the 31st of January.
> or March.  or June.....
> 
> What I ended up doing is using f$cvtime to get the year and month fields,
> prepending a "28-", then asking f$cvtime for the month field 5 days past
> that constructed date.  very messy, but no loopholes I can see.  Any better
> ideas??
> 
Yes, the fact that my solution falls over at certain times of the month was 
pointed out to me by my fellow-worker Don Stokes and his solution was also 
posted.

The solution is as follows:

$ Next_month = f$cvtime ("1-+31-","absolute","month")

This uses a combination time 1- indicates beginning of the current month, 
+31- means add 31 days to the beginning of the month. It only involves one 
lexical call.

I haven't worked out where you are putting the "28-" - this string does not 
appear in your solution.

Martin D. Hunt