On 11 September 2014 00:45, "" <lord.buddha@gmail.com> wrote:
To me the instant 2015-05-13 24:00 actually means 2015-05-14 00:00....  

This is correct, and this is how zic interprets it.
 
Currently we have just Africa/Cairo and Asia/Dhaka using 24:00 as a transition time.

There are a few others; namely, America/Montreal, Asia/Amman, Asia/Gaza, Asia/Hebron, and Europe/Helsinki.
 
Should not these be updated to avoid 24:00 and the ambiguity that arises.
 
On the contrary, 24:00 is meant to be quite unambiguous.  We can't stop governments from ambiguously declaring that rules start "at midnight" without specifying which one.  But we can be clear, when representing those rules, about which midnight we understand to be the correct one to use.

In some cases, that's simpler to express with 00:00; in others, with 24:00.  Africa/Cairo's main (non-Ramadan) rules for the near future are most succinctly expressed with one of each:

Rule    Egypt   2014    max -   Sep lastThu 24:00   0   -
Rule    Egypt   2015    2019    -   Apr lastFri  0:00s  1:00    S

Anyway, the use of 24:00 _seems_ to have broken the JodaTime library.

That may be, but if so, it's been broken for five years.
http://mm.icann.org/pipermail/tz/2014-June/020964.html

--
Tim Parenti