Gigasecond: two tests fail locally probably due to summer time change in timezone

Two tests fail locally although they pass when submitted. Can we find a solution to this?
The possible reason according to Alex Lohr is:

it’s very probably the switch from summer time to winter time breaking the tests. The test servers run fixed on GMT.

Failure → ./gigasecond_spec.lua @ 4 gigasecond date only specification of time ./gigasecond_spec.lua:9: Expected objects to be equal. Passed in: (string) ‘12/31/42’ Expected: (string) ‘01/01/43’

Failure → ./gigasecond_spec.lua @ 36 gigasecond full time with day roll-over ./gigasecond_spec.lua:41: Expected objects to be equal. Passed in: (string) ‘10/03/46’ Expected: (string) ‘10/02/46’

Operating System: Pop!_OS 24.04 LTS
Kernel: Linux 7.1.5-76070105-generic
Architecture: x86-64
Time zone: Europe/Berlin (CEST, +0200)

Can you share your solution?
Do you need to change something to tell Lua to ignore the local timezone and use GMT?