Re: [R] Units of Difference Between Two Dates

From: Prof Brian Ripley <ripley_at_stats.ox.ac.uk>
Date: Thu, 15 May 2008 13:38:50 +0100 (BST)

On Thu, 15 May 2008, Tom La Bone wrote:

>
> I would like all three of these calculations to give an answer in days (or at
> least the same units):
>
>> as.POSIXct("1971-08-01 00:00:00") - as.POSIXct("1971-08-01 00:00:00")
> Time difference of 0 secs
>>
>> as.POSIXct("1971-08-01 12:00:00") - as.POSIXct("1971-08-01 00:00:00")
> Time difference of 12 hours
>>
>> as.POSIXct("1971-09-01 00:00:00") - as.POSIXct("1971-08-01 00:00:00")
> Time difference of 31 days
>>
>
> What is the best way to do this?

Use difftime() explicitly.

-- 
Brian D. Ripley,                  ripley_at_stats.ox.ac.uk
Professor of Applied Statistics,  http://www.stats.ox.ac.uk/~ripley/
University of Oxford,             Tel:  +44 1865 272861 (self)
1 South Parks Road,                     +44 1865 272866 (PA)
Oxford OX1 3TG, UK                Fax:  +44 1865 272595

______________________________________________
R-help_at_r-project.org mailing list
https://stat.ethz.ch/mailman/listinfo/r-help
PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.
Received on Thu 15 May 2008 - 13:04:49 GMT

Archive maintained by Robert King, hosted by the discipline of statistics at the University of Newcastle, Australia.
Archive generated by hypermail 2.2.0, at Thu 15 May 2008 - 13:30:37 GMT.

Mailing list information is available at https://stat.ethz.ch/mailman/listinfo/r-help. Please read the posting guide before posting to the list.

list of date sections of archive