NDB query by time part of DateTimeProperty
The only way would be to store the time of day as a separate property.  An int will be fine, you can store it as seconds.  You could do this explicitly (ie set the time property at the same time you set the datetime, or use a computedproperty to automatically set the value.
I need to query items that where added at some time of day, ignoring which day. I only save the DateTime of when the item was added.
Comparing datetime.Time to DateTimeProperty gives an error, and DateTimeProperty does not have a time() method.