Re: How to: 96 bit Date-time arithmetic?

[Christian Lemburg <lemburg@aixonix.de>]

"Siegfried Heintze" <siegfried@heintze.com> writes:

> How do I add delta times and subtract absolute times stored in the 96 bit (3
> integer) format? Apparently the functions encode and decode will help me
> convert to and from the 96 bit time format.
> 
> I want to increment times by 1 day and have emacs properly figure out when
> there is a Feb 28.


(defun my-emacs-time->seconds (time)
  "Convert emacs time format to seconds as one 32 bit integer."
  (let ((high (lsh (car time) 16))
	(low (cadr time)))
    (logior high low)))

(defun my-seconds->emacs-time (time)
  "Convert one 32 bit integer to emacs time format."
  (list (lsh time -16) (logand time (1- (lsh 1 16))) 0))


-- 
Christian Lemburg, <lemburg@aixonix.de>, http://www.clemburg.com/
 Hand, n.:
 	A singular instrument worn at the end of a human arm and
 commonly thrust into somebody's pocket.
 		-- Ambrose Bierce, "The Devil's Dictionary"