My Realtime script works in Studio but not in the client (press play on the game). It shows just a random time. It's in GMT or BST.
-- Ganondude
local time_zone = -5 -- Time zone, offset from GMT.
local tz_diff = 5*3600 + time_zone*3600
local secondsInDay = 60*60*24
while true do
game.Lighting:setMinutesAfterMidnight(math.fmod(tick() + tz_diff,secondsInDay)/60)
wait(0.1)
end

3 comments
in studio, tick() is from your computer. in roblox servers, its the time from Roblox's server. Run this from a localscript and it should probably work as expected. You can also use os.time() instead of tick(), iirc. which will be the same across any script.
Do i just leave it in Workspace as a local script?
Nevermind, put it into StarterPlayerScripts and it's working. Thanks.