Prior to 1925, the library was open from 8 a.m. to 12:45 p.m., 1:15 to 6 p.m. and from 7 p.m. to a 10 p.m. closing time Mondays through Fridays. On weekends, it was open from 8 a.m. to 12:45 p.m. and from 1:15 p.m. until closing at 6 p.m; it was open on Sundays from 2 p.m. to 5 p.m. The first D. H. Hill Library began operations on a limited basis from November 1925, with hours from 8 a.m. to 1 p.m., 1:30 p.m. to 5 p.m. and from 7 p.m. to 10 p.m. Mondays through Fridays. Effective from January 1926, full-service library hours were from 8 a.m. to 6 p.m. and from 7 p.m. to 10 p.m. Mondays through Fridays. On March 12 1955, when the new D. H. Hill Library was dedicated, its hours were extended through 11 p.m. On December 8, 1967, closing hours were extended to midnight. In 1996, a system of 24-hour service (Sunday night through Thursday night) was instituted. Under this system, D. H. Hill was open 24 hours a day from Monday through Thursday. On Fridays and Saturdays, the Library closed at 10 p.m. On Saturdays and Sundays, the Library opened at 9 a.m. 24-hour service resumed Sunday night.