Insurance covers require a minimum of 24 hours of hospitalization. Insurance covers do not reimburse you for OPD visits, health checkups, or medicines that don't involve a hospitalization.

Note that technological and medical breakthroughs have made it possible for certain treatments and surgeries to be administered and conducted over a few hours. Examples include chemotherapy, radiotherapy, dialysis, cataract surgery, kidney stone removal, etc. These are called daycare procedures as it is performed without requiring 24-hour hospitalization. There are 150 such day care procedures that are covered. You can find the complete list here.