DateTrunc.java

void performFetch() {
	addDateTruncAttribute( editingContext, "SomeEntity", "checkInTimeTruncated", "check_in_time" );
	addDateTruncAttribute( editingContext, "SomeEntity", "requestedTruncated", "requested" );
	EOQualifier q = EOQualifier.qualifierWithQualifierFormat( "checkInTimeTruncated>=requestedTruncated", null );

	// ...finish your fetch using the qualifier
}

static void addDateTruncAttribute( EOEditingContext ec, String entityName, String attributeName, String columnName ) {
	EOAttribute attribute = new EOAttribute();
	attribute.setName( attributeName );
	attribute.setColumnName( columnName );
	attribute.setReadFormat( "date_trunc('day',%P)" );

	EOUtilities.entityNamed( ec, entityName ).addAttribute( attribute );
}