Re: Problem with date calculations in a table

[Nick Dokos <nicholas.dokos@hp.com>]

Chris Randle <chris@amlog.co.uk> wrote:

> Nick Dokos wrote:
> > I've been trying to make a table with the following structure: column
> > 1 contains either a date or is empty; column 2 contains a date that's
> > calculated from the corresponding date in column 1 (if column 1
> > contains a date) or is empty (if column 1 is empty). In the example
> > below, column 2 is supposed to be the date 12 hours or 0.5 days after
> > the date in column 1 (assuming that it is non-empty).     
> 
> I had problems getting date arithmetic to work in tables. I posted my
> findings and solutions here:
> 
> http://article.gmane.org/gmane.emacs.orgmode/6536/
> 
> Don't know if it will fix your problem (too lazy to try!) but I suspect
> it will.
> 

It did! I don't understand the details yet but the following seems to do
what I want:

| start                | ETA (start + 12 hrs)   |
|----------------------+------------------------|
| 2008-08-14 Thu 18:15 | <2008-08-15 Fri 06:15> |
|                      |                        |

#+TBLFM: $2=(date(<$1>) ? <$1>+0.5 : string(""))

The date in the first column can be just a string as above, a passive
date or an active date (the file is not in the agenda list so I don't
really have to worry about active dates).

Thanks very much,
Nick