Can all missed prayers be made up at night for someone whom Allah has guided to prayer after a period of discontinuation, knowing that he works and does not find time to make them up during the day?

You must repent to Allah for abandoning prayers and make up for the missed ones. If the number of missed prayers is unknown, then one must make up a number that is most likely to clear their conscience, as Allah Almighty says: (So fear Allah as much as you are able). One should not be preoccupied from making up the obligatory prayers except by what is necessary to earn a livelihood. If no time is found for making up prayers except at night, then one should do so.