On 12/01/2017 14:09, Tim Ward wrote:

> Sorry if this is a really basic question, but some time spent
> searching has failed to find for me the definitive detailed
> documentation on exactly how Firebird handles time zones (I'm
> particularly interested, to start with, in using CURRENT_TIMESTAMP to
> create a value in a TIMESTAMP field, and later reading it out and
> using it to display in a UI, but that's only to start with).
>
> Can someone point me in the right direction please?

So to summarize the replies (thanks all):

(1) Firebird does not attempt to do anything at all with time zones, and
has no concept of UTC.

(2) CURRENT_TIMESTAMP and its relatives ask the operating system for
current wall clock time.

(3) This is what gets stored and read back out of tables, with no time
zone manipulation.

(4) So if for example CURRENT_TIMESTAMP is called when it's 0700 UTC but
0500 local wall clock time as configured in the operating system, then
the value will be 0500 at all times and places in Firebird (unless
arithmetic is done in it by explicit application code).

(I'm trying to understand the behaviour of an existing system here, not
design anything new.)

--
Tim Ward