describes the feeling of finally managing to resolve the issue or problem (dark clouds on the sky– which finally disappear [negative]) and feeling relieved again (seeing the sun which is sunny and bright again [positive])
Definitions (粵典–words.hk)
語句、俚語
形容所有煩惱、麻煩都解決晒，令人鬆返口氣 everything is finally solved; all bad things have gone; feeling relieved; literally: the sky finally brightens up
終於傾得成，今次一天都光晒喇。
终于倾得成，今次一天都光晒喇。
zung1 jyu1 king1 dak1 seng4, gam1 ci4 jat1 tin1 dou1 gwong1 saai3 laa3. I have finally closed the deal, everything is going to be alright now.
終於考完試，真係一天都光晒。
终于考完试，真系一天都光晒。
zung1 jyu1 haau2 jyun4 si5, zan1 hai6 jat1 tin1 dou1 gwong1 saai3. Finally I have finished all the exams. I am so relieved now.