A landlord has to make repairs often enough to keep the place habitable and in a safe living condition.
If something needs repaired the landlord should have it fixed within a day or so and if something is an emergency the landlord has from 24 to 48 hours to get the repair done or hire someone to get the repair done.
There's no set amount of time to as how often a landlord has to make repairs on the place but they must have the apartment or house maintained enough to be in a safe and livable condition.