Re: Converting local time to another time zone

On 10 Apr 2013 14:09, rick baird wrote:

<<SNIP>>
My questions are these:

Is there an API I can use (V5R4 and lower) to retrieve the list of
valid time zones listed in the WRKTIMZON?

Can I somehow retrieve the UTC offset for a particular time zone?
According to the help, this offset does not self adjust for daylight
savings time, so are the dates the time zone springs forward and
back stored somewhere? How does the operating system know how to
spring forward and back? Is that only stored for local time, or by
time zone?

I'm hoping to not have to store the time zones, offsets and DST
dates myself if I can help it, but if that's the best way to go,
then I need to get started on that.

Seems the desire is to have most of what WRKTIMZON presents?

Perhaps the following would assist in that regard?:

http://publib.boulder.ibm.com/infocenter/iseries/v5r4/topic/apis/qwcrtvtz.htm
Retrieve Time Zone Description (QWCRTVTZ) API
"...
The Retrieve Time Zone Description (QWCRTVTZ) API retrieves information about one or more time zone descriptions. A time zone description contains information that is used to calculate a local time.
...

Format RTMZ0100

The RTMZ0100 format returns the following information for the specified time zone description.

Offset Offset Type Field
-Dec- -Hex-
0 0 BINARY(4) Bytes returned
4 4 BINARY(4) Bytes available
8 8 BINARY(4) Number of time zone descriptions available
12 C BINARY(4) Offset to time zone descriptions
16 10 BINARY(4) Number of time zone descriptions returned
20 14 BINARY(4) Length of a time zone description entry
24 18 CHAR(*) Reserved
These fields repeat, in the order listed, for the number of time zone descriptions returned.
CHAR(10) Time zone description name
CHAR(1) Local system time indicator
CHAR(1) Daylight Saving Time indicator
BINARY(4) Offset from UTC
CHAR(10) Standard Time abbreviated name
CHAR(50) Standard Time full name
CHAR(10) Daylight Saving Time abbreviated name
CHAR(50) Daylight Saving Time full name
CHAR(7) Standard Time message
CHAR(7) Daylight Saving Time message
CHAR(10) Message file name
CHAR(10) Message file library name
CHAR(2) Daylight Saving Time start - month
CHAR(1) Daylight Saving Time start - day
CHAR(1) Daylight Saving Time start - relative day of month
CHAR(6) Daylight Saving Time start - time
CHAR(2) Daylight Saving Time end - month
CHAR(1) Daylight Saving Time end - day
CHAR(1) Daylight Saving Time end - relative day of month
CHAR(6) Daylight Saving Time end - time
CHAR(50) Text description
CHAR(*) Reserved
...
API introduced: V5R3"