<font size=2 face="sans-serif">To whom it may concern,</font>
<br>
<br><font size=2 face="sans-serif">I am writing to report an issue I have
discovered in the recent change to the Asia/Dhaka time zone data, which
recently implemented daylight saving time in June. The recent update to
the time zone data (tzdata2009j) includes a start date for daylight saving
time, but no end date. Intuitively, daylight saving time should have a
start and an end date within the same year, otherwise what is implemented
is an indefinite GMT offset change. Because of this programs that detect
DST rules may see the absence of an end to the DST period as an error.
This may cause programs which obtain DST rules using Olson time zone data
to fail to detect daylight saving time rules for Asia/Dhaka. For completeness,
I propose a tentative end date be implemented now, and an updated date
be implemented once an official date is released, or the government releases
an additional tentative date in September. </font>
<br>
<br><font size=2 face="sans-serif">According to timeanddate.com:</font>
<br>
<br><font size=2 face="sans-serif"> "The
press secretary did not confirm the length of DST but stated that the government
would decide the DST end date and would announce it later. On another note,
Bangladesh's minister for power said earlier in 2009 that the new timing
might continue
until the end of September. Timeanddate.com will provide an update on the
DST end date when it becomes available. "</font>
<br>
<br><font size=2 face="sans-serif"> (</font><a href="http://www.timeanddate.com/news/time/bangladesh-daylight-saving-2009.html"><font size=2 face="sans-serif">http://www.timeanddate.com/news/time/bangladesh-daylight-saving-2009.html</font></a><font size=2 face="sans-serif">):</font>
<br>
<br><font size=2 face="sans-serif">Timeanddate.com picked September 25th,
which seems like a likely enough date. I have update the tzdata on my system
with the following rules to implement this change.</font>
<br>
<br><font size=2 face="sans-serif"># Rule NAME FROM
TO TYPE IN
ON AT
SAVE LETTER/S</font>
<br><font size=2 face="sans-serif">Rule Dhaka09
2009 max
- Jun
19 23:00
1:00 D</font>
<br><font size=2 face="sans-serif">Rule Dhaka09
2009 max
- Sep
26 00:00
0:00 S
</font>
<br>
<br><font size=2 face="sans-serif"># Zone NAME
GMTOFF
RULES FORMAT
[UNTIL]</font>
<br><font size=2 face="sans-serif">Zone Asia/Dhaka
6:01:40 - LMT
1890</font>
<br><font size=2 face="sans-serif">
5:53:20
- HMT
1941 Oct # Howrah Mean
Time?</font>
<br><font size=2 face="sans-serif">
6:30
- BURT
1942 May 15 # Burma Time</font>
<br><font size=2 face="sans-serif">
5:30
- IST
1942 Sep</font>
<br><font size=2 face="sans-serif">
6:30
- BURT
1951 Sep 30</font>
<br><font size=2 face="sans-serif">
6:00
- DACT
1971 Mar 26 # Dacca Time</font>
<br><font size=2 face="sans-serif">
6:00
Dhaka09 B%sT
# Bangladesh Time</font>
<br>
<br><font size=2 face="sans-serif">Could you please evaluate this change
for inclusion in the Olson time zone data? Please let me know if you have
any questions or concerns. </font>
<br>
<br><font size=2 face="sans-serif">Thanks, </font>
<br>
<br><font size=2 face="sans-serif">Nik</font>
<br>