The Memorial grounds are accessible 24 hours a day, 365 days a year. Rangers are on-site daily from 9:00a.m.-5:30p.m. and on-site from 9:00a.m.-9:00p.m. on Friday, Saturday and Sunday to provide information from Memorial Day weekend through Labor Day weekend and from 9:00 a.m. - 5:30 p.m. Labor Day through Memorial Day. Rangers will not be available on Thanksgiving, Christmas or New Year's Days.

The Oklahoma City National Memorial Museum is open 7 days a week between 9:00 a.m. and 6:00 p.m. Monday - Saturday and 1:00 p.m. - 6:00 p.m. on Sunday with ticket sales stopping one hour prior to closing.