From John.Marsland at CommerzbankIB.com  Fri Oct 10 13:51:48 2003
From: John.Marsland at CommerzbankIB.com (Marsland, John)
Date: Fri Oct 10 13:51:08 2003
Subject: [Rd] R1.8.0 : seq.POSIXt() problems
Message-ID: <8CBAA121CEB4D5118CB200508BB2BBEF0317E9DB@xmx8lonib.lonib.commerzbank.com>

I'm having problems with seq.POSIXt() under R 1.8.0 (Windows NT4).

Essentially the last date in my sequence is lost depending on whether the
sequence spans a daylight saving time change. 

This seems to apply regardless as to whether one uses by="DSTdays" or
by="days".

Try the following lines of code:

> seq.POSIXt(as.POSIXct("2003-09-01"),as.POSIXct("2003-10-09"),"DSTdays")
[1] "2003-09-01 GMT Daylight Time" "2003-09-02 GMT Daylight Time"
...
[39] "2003-10-09 GMT Daylight Time"

> seq.POSIXt(as.POSIXct("2003-03-01"),as.POSIXct("2003-10-09"),"DSTdays")
[1] "2003-03-01 GMT Standard Time" "2003-03-02 GMT Standard Time"
...
[221] "2003-10-07 GMT Daylight Time" "2003-10-08 GMT Daylight Time"

> seq.POSIXt(as.POSIXct("2002-10-01"),as.POSIXct("2003-10-09"),"DSTdays")
[1] "2002-10-01 GMT Daylight Time" "2002-10-02 GMT Daylight Time"
...
[373] "2003-10-08 GMT Daylight Time" "2003-10-09 GMT Daylight Time"

Any thoughts?

Regards,

John

> R.version
         _              
platform i386-pc-mingw32
arch     i386           
os       mingw32        
system   i386, mingw32  
status                  
major    1              
minor    8.0            
year     2003           
month    10             
day      08             
language R   


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[Rd] R1.8.0 : seq.POSIXt() problems
Marsland, John