Generally, the Special Collections reading room hours are as follows:

Monday: 9:00am – 4:00pm
Tuesday: 9:00am – 6:00pm
Wednesday: 9:00am – 4:00pm
Thursday: 9:00am – 4:00pm
Friday: 9:00am – 4:00pm
Saturday, Sunday: CLOSED

Please check this site for information about specific hours, especially during breaks: https://www.lib.uiowa.edu/sc/hours