tzdata timezone boundaries

Hello,

Is there a way to have access to the tzdata boundaries from within postgres
?

the zdump linux command gives something like

------
zdump -v /usr/share/zoneinfo/America/Los_Angeles | grep 2017

Sun Mar 12 09:59:59 2017 UTC = Sun Mar 12 01:59:59 2017 PST isdst=0
gmtoff=-28800
Sun Mar 12 10:00:00 2017 UTC = Sun Mar 12 03:00:00 2017 PDT isdst=1
gmtoff=-25200
Sun Nov 5 08:59:59 2017 UTC = Sun Nov 5 01:59:59 2017 PDT isdst=1
gmtoff=-25200
Sun Nov 5 09:00:00 2017 UTC = Sun Nov 5 01:00:00 2017 PST isdst=0
gmtoff=-28800
------

I guess that postgres have access to these datas to be able to correcly
handle timezone, but I can't find a way to surface these boundaries (except
maybe with a smart generate_series scheme (?))

nb: I asked the question on stack overflow to no avail -
https://stackoverflow.com/questions/45381924/postgresql-how-to-extract-a-list-of-past-and-known-future-offset-changes-for-a

Thanks,
Jérôme Wagner