> An optional `show` parameter would be a possible enhancement beyond that,
> although I don't know how useful it would be; if it isn't passed, the
> default should be 0 (unlimited). --[[smcv]]
+
+----
+
+## bug?: all albums and pages become interdependent
+*(ikiwiki master branch 2014-06-06 and smcv album4 branch)*
+
+On a site with the following structure where all album$n.mdwn files have the ``[[!album]]`` directive set. All albums and albumviewers get rebuilt whenever any one of the pages is touched and the command ``ikiwiki --setup debug.setup --refresh --verbose`` is issued.
+
+ /index.mdwn
+ |-album01.mdwn
+ |-album01/
+ | |-imgA.jpg
+ | |-imgB.jpg
+ |
+ |-album02.mdwn
+ |-album02/
+ | |-imgC.jpg
+ | |-imgD.jpg
+ |
+ |-album03.mdwn
+ |-album03/
+ | |-imgE.jpg
+ | |-imgF.jpg
+
+This happens even if the indexpage has no links and when the tree is one level deeper than above with a folder between the index and each ``album$0n`` tuple. Touching index.mdwn rebuilds for instance imgF viewer and output like for example the following as a result of changing ``album01.mdwn`` and issuing ``ikiwiki --setup debug.setup --refresh --verbose``
+
+ building album02/imgC, its previous or next page has changed
+ building album03/imgE, its previous or next page has changed
+ building album02.mdwn, which depends on album02/imgC
+
+In other words using the album plugin means all changes trigger full rebuilds (as far as I can tell). With my workflow this hasn't been much of an issue as my sites are static and updated maximum once a week but it does make comments unfeasible.
+
+Perhaps there is something in my setup that triggers this problem? If anyone has an ikiwiki album installation where ``--refresh`` limits the scope of the rebuild to just one album I'd be interested to hear. See <http://img.kalleswork.net> for an live website that has this problem. I've tested a simpler debug site without any customization as well. --[[kjs]]
+
+
--- /dev/null
+[[!template id=plugin name=datetime_cmp author="[[Louis|spalax]]"]]
+[[!tag type/pagespec]]
+
+# Datetime_cmp
+
+This plugin provides a family of
+[pagespec](http://ikiwiki.info/ikiwiki/pagespec/) matching pages according to
+creation or modification times.
+
+It also sets the date of the next modification of the page on relevant date, so
+that the page will be rebuilt if the condition changes.
+
+## List of functions
+
+The list of functions is given by the following regexp:
+
+ [ct](date|time)_(lt|gt|leq|geq|eq|neq)_(abs|page|now|today)(|_delta)
+
+where:
+
+ * `[ct]`: compare creation or modification time or date:
+ * `c`reation time;
+ * `m`odification time.
+ * `(date|time)`: compare full date and time, or only date (useful when time is irrelevant):
+ * `time`: compare full date and time;
+ * `date`: compare only date.
+ * `(lt|gt|leq|geq|eq|neq)`: operator of comparison:
+ * `lt`: less than;
+ * `gt`: greater than;
+ * `leq`: less or equal than;
+ * `geq`: greater or equal than;
+ * `eq`: equal;
+ * `neq`: not equal.
+ * `(abs|page|now|today)`: element to compare to:
+ * `abs`: absolute date or time (given in argument);
+ * `page`: other page (given in argument);
+ * `now`: date or time of compilation;
+ * `today`: same meaning as `now`.
+ * `(|_delta)`: used to add a time delta (to use comparisons such as *created at least two day after `some_page`*):
+ * *empty*: no delta;
+ * `_delta`: delta (given in argument).
+
+### Number of arguments
+
+[[!table header=no data="""
+ | `now` `today` | `page` | `abs`
+no delta | *no arguments* | `pagename` | `date`
+delta | `delta` | `pagename, delta` | `date, delta`
+"""]]
+
+### Format of arguments
+
+* *date* or *time*: anything that can be recognized by perl [[str2time|http://search.cpan.org/~rse/lcwa-1.0.0/lib/lwp/lib/HTTP/Date.pm]] function, *without any comma*.
+* *delta*: One of the following patterns:
+ * `Y-M-D`: positive date;
+ * `H:M:S`: positive time;
+ * `Y-M-D H:M:S`: positive date and time;
+ * Add `-` at the beginning of the string to make durations negative.
+* several arguments: when two arguments are provided, they are passed as one string, which is then split according to the last comma.
+
+## Time zones
+
+Key `timezone` in the setup file is used to define time zone. If not set, we
+try to guess the local time zone.
+
+## Examples
+
+### Some functions
+
+* `ctime_gt_page(foo)`: match pages created after page `foo`.
+* `cdate_eq_today()`: match pages created the day the wiki is compiled.
+* `mtime_eq_now()`: match pages modified the time the wiki is compiled (likely no page, since comparison is done up to the milisecond).
+* `cdate_geq_page_delta(foo, 00-00-01)`: match pages created at least one day after page `foo`.
+* `cdate_gt_page(foo)`: same as the previous one.
+* `mdate_gt_today_delta(-00-01-00)`: match pages modified one month ago, or later (can be used to display recent changes).
+
+### Use case
+
+It can be used to display a list of upcoming events.
+
+ \[[!inline pages="events/* and cdate_geq_today()" reverse=yes sorted=meta(date)]]
+
+## Code
+
+Code and documentation this way: [[https://atelier.gresille.org/projects/gresille-ikiwiki/wiki/datetime_cmp]].
-Hello, welcome to my page.
-
There isn't much to say, I'm just a person of the common kind,
-trying to make this world a bit better for the next generations :-)
+trying to make this world a bit better for the next generations.
-As part of my personal tiny fight for privacy and freedom of speech,
-I launched my website via I2P and Tor only. This will probably change soon,
-because there's a non-centralized cooperative way to use DNS, but
-for now that's all there is. My source code is there too.
+I run a website, you're welcome to visit.
-* Tor: <http://75dae7c76okcrloz.onion>
+* Clearnet: <http://www.partager.null> (requires [OpenNIC])
* I2P: <http://partager.i2p>
+* Tor: <http://75dae7c76okcrloz.onion>
+
+[OpenNIC]: https://www.opennicproject.org/