Format Strings for Date and Time

Where can I find a list of valid strings for date and time columns?  I'm using the Orion Report Writer and have a Date and Time field that I'd like to format as mm/dd/yy hh:mm so it doesn't take up so much room on the report/wrapping.

I have: 

field format:  Date and Time

Format String: mm/ddyy hh:mm

but it doesn't appear to be using the format.  No errors either.

This is a custom sql report.