How do I print os.time?

Normal Lua has a function os.date to format times. Unfortunately, ROBLOX lacks this function.

You can use a ModuleScript that someone else has written to do this for you (there are a few, I've made on here).

While date-time is fairly problematic, just hours and minutes isn't so bad.

In Unix time, every day has precisely 86400 seconds in it; a minute has precisely 60 seconds and an hour has precisely 60 minutes.

Then

local now = os.clock() -- in seconds
local second = now % 60
now = (now - second)/60 -- in minutes
local minute = now % 60
now = (now - minute)/60 -- in hours

if minute < 10 then
    print(hour .. ":0" .. minute)
else
    print(hour .. ":" .. minute)
end