The library's Service Desk is located within the Knowledge Center on the lobby level of the Hammer Building.

Service Desk Hours
 Monday - Thursday  9 am to 7 pm
 Friday  9 am to 5 pm
 Saturday  CLOSED
 Sunday  Noon to 8 pm

**The Service Desk will close early on Friday, July 21st at 1pm.**

15 minutes before closing time all circulation transactions should be completed.

The Knowledge Center space will remain open for 24-hour access to CUMC students, faculty, and staff only.  At the end of staffed hours, library staff will check IDs.  Knowledge Center guests without a CUMC ID will be asked to leave.  CUMC affiliates will have after-hours access via card swipe.

The Columbia University Libraries website has a calendar view of the schedule above and hours for other libraries such as Barnard and the Digital Humanities Center.

Holiday Closings

The service desk will be closed on the following holidays for the 2017/2018 academic year.  The Knowledge Center space will remain accessible via card access.

Labor Day September 3-4, 2017
Thanksgiving November 23-26, 2017
Christmas December 24-26, 2017
New Year's Day December 31, 2017 - January 2, 2018
Martin Luther Jr.'s Birthday January 14-15, 2018
President's Day February 18-19, 2018
Memorial Day May 27-28, 2018
Independence Day July 4, 2018

Interlibrary Loan (ILL)

Monday - Friday, 9am to 5pm.

Archives & Special Collections

Monday - Friday, 9:15am to 4:45pm, by appointment only. Telephone and email reference is available Monday - Friday, 9am to 5pm. Please contact the Archives & Special Collections at hslarchives@columbia.edu for more information