Last modified: 2007-03-21 18:22:06 UTC
The motivation for this request is to provide a way that would allow Wikibooks to put up a featured Wikibook on the main page that would appear on a rotation schedule, similar to what is done for Wikipedia and Commons Featured Articles/Pictures. The short coming of this concept is that Wikibooks simply doesn't have enough quality books to justify or warrant having a new book featured every day that is brand new. I've created a template that currently uses a calculation using a mod function and a psuedo "variable" that is really just a transcluded template: {{Wikibooks:Featured Books/Book{{#expr: {{CURRENTDAY}} mod {{FEATURENUM}}}}}} The problem here is that the CURRENTDAY variable only goes to 31 (on months with 31 days), and we need the ability to have a few more than just 31 featured Wikibooks (although this is a short term solution). What I would like to see is something more like this: {{Wikibooks:Featured Books/Book{{#expr: {{JULIANDAY}} mod {{FEATURENUM}}}}}} where the variable "JULIANDAY" is calculated according to the rough standards listed on [[w:Julian Day]]. I believe this value is already calculated by MySQL and other DB servers, so it is simply a matter of passing this information forward, although calculations of this date aren't overly complicated. I'm sure that a very complicated expression could also be generated using the values of "CURRENTDAY", "CURRENTMONTH", and "CURRENTYEAR" to derive this date, although it could be debated if the efficiency of doing this for something like a major project main page is something worth doing. It also seems a bit strange to "recalculate" a variable that already exists in the operating system and was used to calculate the above three variables in the first place, or at least something very similar. This does have value beyond just the very limited appeal for having a date variable that can be manipulated for further calculations, and I think that this is certainly something that can be extended in other directions as well.
Wouldn't something like {{#expr:({{#date:U}}/86400) round 0}} work for you?
A better expression would be: {{#expr:{{#time:U}}/86400 round 0}} but yeah, that mostly does what I was looking for. Thanks. I'm going to create a full Julian date template based off of this, which is trivial at this point. Thank for pointing me in the right direction. The only real problem here is the classical Unix MAXINT bug for when this number rolls over, but I think that will be a larger issue for more than just the main page of Wikibooks. Hopefully that bug will get a good work around that will be better than the Y2K problems.
