The sqlite3 timestamp conversion between unixepoch and localtime can't be done according to the timezone setting on the machine automatically.

[MRAB]

On 2021-09-02 08:40, Alan Gauld via Python-list wrote:
> On 31/08/2021 23:31, Chris Angelico wrote:
> 
>> Ah, good to know. I think that actually makes a lot of sense; in the
>> US, they try to let everyone pretend that the rest of the world
>> doesn't exist ("we always change at 2AM"), but in Europe, they try to
>> synchronize for the convenience of commerce ("everyone changes at 1AM
>> UTC").
> 
> There's another gotcha with DST changes. The EU and USA have different
> dates on which they change to DST.
> 
> In one of them (I can't recall which is which) they change on the 4th
> weekend of October/March in the other they change on the last weekend.
> 
> That means on some years (when there are 5 weekends) there is a
> week when one has changed and the other hasn't. That caused us
> a lot of head scratching the first time we encountered it because
> our service centres in the US and EU were getting inconsistent
> time reporting and some updates showing as having happened in
> the future!
> 
In the EU (and UK) it's the last Sunday in March/October.

In the US it's second Sunday in March and the first Sunday in November.

I know which one I find easier to remember!