Timezones for dates with MySQL storage

[Andrew Wasielewski]

I am running GnuCash 2.4.13 with MySQL storage.  I now need to develop some custom reports using SQL.

I can get the transaction date from "post_date" in the "transactions" table.  Although GnuCash doesn't appear to make use of the time, it is stored as a datetime in MySQL.

I am confused by the (apparent) use of timezones.  I am in UK; it is currently Summer Time (UTC + 1), and all my transactions have been entered in the last couple of weeks (i.e. since Summer Time started).

Sometimes the post_date is midnight at the start of the posting date; other times it is 23:00 on the day before (i.e. different by the current TZ offset from UTC).  This occurs with scheduled transactions, and transactions generated from the *same* schedule display both behaviours.  Other times the time appears to be the actual entry time, but on the correct posting date.

GnuCash obviously "knows" what the posting date is, as it always shows the correct date.  My question is:- what SQL logic can I apply to consistently get the correct posting date?  

As a follow up, am I safe to assume that GnuCash won't have any problem when Summer Time ends and local time reverts to UTC?  I am most unlikely to need to change the system TZ toanything other than UK...


Thanks for any advice,
Andrew