I've gotten the TimeTextBox to work, sort of, in a grid by including a dojo.declare in the script section of my JSP:

dojo.declare(
	"dojox.grid.editors.TimeTextBox", dijit.form.editors.Dijit,
	{	

..

But, I can't get the result to format properly. I keep getting a full date/time like: Sat Jan 01 1972 14:00:00 GMT-0500 (Eastern Standard Time) instead of just "HH:MM A".

I've tried

dojo.declare("dojox.grid.editors.TimeTextBox", dijit.form.editors.Dijit,{
	editorClass: "dijit.form.TimeTextBox",