Comment 63 for bug 365065

(In reply to John Ralls from comment #42)
> If you're willing to change the timezone on the computer back to New Zealand
> long enough to open and re-save the file, it will be easier: In that case
> just search and replace +1200 to whatever is your offset and save. Change
> the timezone back and open it in GnuCash and everything should be OK.

I was in New Zealand again for a few weeks. Since I have come back I have not used GnuCash again, so the file is still at GMT+12. I had a look now, and saw a few things to watch out for.

Some of the transactions have the following tags:
  <trn:date-posted>
    <ts:date>2016-04-26 00:00:00 +1200</ts:date>
  </trn:date-posted>
  <trn:date-entered>
    <ts:date>2016-05-01 13:02:43 +1200</ts:date>
  </trn:date-entered>
  <trn:slots>
    <slot>
      <slot:key>date-posted</slot:key>
      <slot:value type="gdate">
        <gdate>2016-04-26</gdate>
      </slot:value>
    </slot>
  </trn:slots>

From the date entered I can see this was done in New Zealand, (and it has the +1200), so I can just change the +1200 to +0200 (Home is am at GMT+2)

However I also see these
  <trn:date-posted>
    <ts:date>2016-03-26 11:00:00 +1300</ts:date>
  </trn:date-posted>
  <trn:date-entered>
    <ts:date>2016-04-03 04:04:30 +1200</ts:date>
  </trn:date-entered>
  <trn:slots>
    <slot>
      <slot:key>date-posted</slot:key>
      <slot:value type="gdate">
        <gdate>2016-03-26</gdate>
      </slot:value>
    </slot>

and
  <trn:date-posted>
    <ts:date>2016-07-20 10:00:00 +1200</ts:date>
  </trn:date-posted>
  <trn:date-entered>
    <ts:date>2016-06-22 23:03:46 +1200</ts:date>
  </trn:date-entered>
  <trn:slots>
    <slot>
      <slot:key>date-posted</slot:key>
      <slot:value type="gdate">
        <gdate>2016-07-20</gdate>
      </slot:value>
    </slot>
  </trn:slots>

From the posted date, it looks like these was posted when I was still at home (00:00:00 +0200) and then updated by Gnucash to (11:00:00 +1300) and (10:00:00 +1200) when I was in New Zealand. The first was during daylight saving in New Zealand and the second normal time in New Zealand.

The gotcha here is that you cannot just replace (+1200) with (+0200). The search must also include the time, so search for (00:00:00 +1200). This may also be an edge condition to look out for in the scrub function.