A single setting was added to the jQuery Calendar class: timeSeparators. It takes an array of strings as an argument with the following members:
Examples of the time descriptor format are timeSeparators:[' ',':'] for the 24 hour format and timeSeparators:[' ',':','AM','PM'] for the AM/PM format.
Update: I have fixed some bugs since the original publication. Thanks to everyone who emailed me patches!
Be advised: The time picker may be buggy and/or the original jQuery Calendar functionality may be hampered. Use this version at own risk and check the original version before blaiming jQuery Calendar authors for any bugs or requesting support from them!