Sort Dates Asc does not preserve time (and desc)

[bryantaustin13]

Steps to dupe:

<?xml version="1.0" encoding="utf-8"?>
<tests xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://hl7.org/fhirpath/tests" xsi:schemaLocation="http://hl7.org/fhirpath/tests ../../testSchema/testSchema.xsd"
	   name="CqlListOperatorsTest">
	<capability code="interval-operators"/>
	<group name="SingleTest" version="1.0">
		<test name="SortDatesAsc" version="1.0">
			<expression>({ DateTime(2012, 10, 5, 10), DateTime(2012, 1, 1), DateTime(2012, 1, 1, 12), DateTime(2012, 10, 5) }) S sort asc</expression>
			<output>{ @2012-01-01T, @2012-01-01T12, @2012-10-05T, @2012-10-05T10 }</output>
		</test>
	</group>
</tests>

actual output: "actual": "@2012-01-01T,@2012-01-01T,@2012-10-05T,@2012-10-05T",
Notice that the 12 and 10 are missing from the second and fourth elements.
Possible culprits are the sort comparison (normalizing everything to day precision), or the stringification/serialization of the result (printing only date precision). My bet would be on the serialization.