<!DOCTYPE html>
<html>

<head>
    <meta http-equiv="X-UA-Compatible" content="IE=edge" />
    <meta charset="UTF-8">
    <title>SAPUI5 Navigation</title>
    <script id="sap-ui-bootstrap" 
            src="https://openui5.hana.ondemand.com/resources/sap-ui-core.js" data-sap-ui-theme="sap_bluecrystal" data-sap-ui-libs="sap.m" data-sap-ui-bindingSyntax="complex" data-sap-ui-compatVersion="edge" data-sap-ui-preload="async" data-sap-ui-resourceroots='{
					"demo.mockserver": "./"
				}'>
    </script>

    <script>
        // GLOBALS for debugging reasons;
        var oODataModel,
            oDatePicker,
            oTimePicker,
            oDateTimePicker;
        
        sap.ui.getCore().attachInit(function() {
            sap.ui.require([
                "demo/mockserver/mock/mockserver",

            ], function(mockserver) {
                mockserver.init();

                function handleChange(oEvent) {
                  
                    var sValue = oEvent.getParameter("value");
                    var bValid = oEvent.getParameter("valid");

                    console.log("value", sValue);
                    console.log("is valid", bValid);
                    console.log(oEvent);
                }

                var sServiceURL = "/here/goes/your/serviceUrl/";
                var oModel = new sap.ui.model.odata.v2.ODataModel(sServiceURL);
                
                oODataModel = oModel;
                
                oModel.setDefaultBindingMode(sap.ui.model.BindingMode.TwoWay);
                oModel.setUseBatch(false);
                sap.ui.getCore().setModel(oModel);

                // only display the date!
                var oDate = new sap.m.DatePicker("datepicker", {
                    value: {
                        path: 'date',
                        type: 'sap.ui.model.type.Date',
                        formatOptions: {
                            style: 'full'
                        }
                    }
                });

                oDate.attachChange(handleChange);
                oDatePicker = oDate;

                // display the time field
                var oTime = new sap.m.TimePicker("timepicker", {
                    value: {
                        path: 'time',
                        type: 'sap.ui.model.odata.type.Time'
                    }
                });

                oTime.attachChange(handleChange);
                oTimePicker = oTime;

                var oDateTime = new sap.m.DateTimeInput("datetimepicker", {
                    type: "DateTime",
                    value: {
                        path: 'datetime',
                        type: 'sap.ui.model.odata.type.DateTime',
                        formatOptions: {
                            style: 'short'
                        }

                    }
                });
                
                oDateTime.attachChange(handleChange);
                oDateTimePicker = oDateTime;

                var oText = new sap.m.Text({
                    text: "{date}"
                });

                var oPanel = new sap.m.Panel("panel");

                oPanel.addContent(oDate);
                oPanel.addContent(oTime);
                oPanel.addContent(oDateTime);
                oPanel.addContent(oText);

                var oPageMaster = new sap.m.Page("masterPage", {
                    title: "Supplier Overview",
                    content: [oPanel]
                });

                oPageMaster.bindElement("/datetime('0000000012')")

                var oApp = new sap.m.App();
                oApp.addPage(oPageMaster);
                oApp.placeAt("content");
            });
        });
    </script>

</head>

<body class="sapUiBody" id="content">
</body>

</html>
Try do change the time in the timepicker.

After that the oODataModel.getPendingChanges() has no entries... 
Also the value in the model is not updated.

Debugging variables:

(choose run.plnkr.co in the Console "frame")

var oODataModel,
    oDatePicker,
    oTimePicker,
    oDateTimePicker;

oODataModel.getProperty("/datetime('0000000012')/time");
oODataModel.getProperty("/datetime('0000000012')/date");
oODataModel.getProperty("/datetime('0000000012')/datetime");

oODataModel.getObject("/datetime('0000000012')")
sap.ui.define([
    "sap/ui/core/util/MockServer"
], function(MockServer) {
    "use strict";

    var _sAppModulePath = "demo/mockserver",
        _sJsonFilesModulePath = "mock/mockdata";

    return {

        init: function() {
            var sManifestUrl = jQuery.sap.getModulePath(_sAppModulePath + "/manifest", ".json");
            var sJsonFilesUrl = _sJsonFilesModulePath;

            var oManifest = jQuery.sap.syncGetJSON(sManifestUrl).data;

            var oMainDataSource = oManifest["sap.app"].dataSources.dataRemote;
            var sMetadataUrl = "mock/metadata.xml";

            // create
            var oMockServer = new MockServer({
                rootUri: oMainDataSource.uri
            });

            // configure
            MockServer.config({
                autoRespond: true,
                autoRespondAfter: 1000
            });

            // simulate
            oMockServer.simulate(sMetadataUrl, {
                sMockdataBaseUrl: sJsonFilesUrl
            });

            // start
            oMockServer.start();
        }
    };
});
{
	"sap.app": {
		"dataSources": {
			"dataRemote": {
				"uri": "/here/goes/your/serviceUrl/",
				"type": "OData",
				"settings": {
					"odataVersion": "2.0",
					"localUri" : "mock/metadata.xml"
				}
			}
		}
	}
}
<?xml version="1.0" encoding="utf-8" standalone="yes"?>
<edmx:Edmx Version="1.0" xmlns:edmx="http://schemas.microsoft.com/ado/2007/06/edmx">
    <edmx:DataServices xmlns:m="http://schemas.microsoft.com/ado/2007/08/dataservices/metadata" m:DataServiceVersion="2.0">
        <Schema Namespace="d000000trial.dev.sapui5_date_poc.service.datetime" xmlns:d="http://schemas.microsoft.com/ado/2007/08/dataservices" xmlns:m="http://schemas.microsoft.com/ado/2007/08/dataservices/metadata" xmlns="http://schemas.microsoft.com/ado/2008/09/edm">
            <EntityType Name="datetimeType">
                <Key>
                    <PropertyRef Name="id" />
                </Key>
                <Property Name="id" Type="Edm.String" Nullable="false" MaxLength="10" />
                <Property Name="date" Type="Edm.DateTime" />
                <Property Name="time" Type="Edm.Time" />
                <Property Name="datetime" Type="Edm.DateTime" />
            </EntityType>
            <EntityContainer Name="datetime" m:IsDefaultEntityContainer="true">
                <EntitySet Name="datetime" EntityType="d000000trial.dev.sapui5_date_poc.service.datetime.datetimeType" />
            </EntityContainer>
        </Schema>
    </edmx:DataServices>
</edmx:Edmx>
{
    "d": {
        "results": [{
            "__metadata": {
                "type": "d000000trial.dev.sapui5_date_poc.service.datetime.datetimeType",
                "uri": "https://s8hanaxs.hanatrial.ondemand.com:443/d000000trial/dev/sapui5_date_poc/service/datetime.xsodata/datetime('0000000000')"
            },
            "id": "0000000000",
            "date": "\/Date(489369600000)\/",
            "time": "PT11H11M0S",
            "datetime": "\/Date(-210866803200000)\/"
        }, {
            "__metadata": {
                "type": "d000000trial.dev.sapui5_date_poc.service.datetime.datetimeType",
                "uri": "https://s8hanaxs.hanatrial.ondemand.com:443/d000000trial/dev/sapui5_date_poc/service/datetime.xsodata/datetime('0000000001')"
            },
            "id": "0000000001",
            "date": "\/Date(489369600000)\/",
            "time": "PT11H11M0S",
            "datetime": "\/Date(489409211000)\/"
        }, {
            "__metadata": {
                "type": "d000000trial.dev.sapui5_date_poc.service.datetime.datetimeType",
                "uri": "https://s8hanaxs.hanatrial.ondemand.com:443/d000000trial/dev/sapui5_date_poc/service/datetime.xsodata/datetime('0000000002')"
            },
            "id": "0000000002",
            "date": "\/Date(489369600000)\/",
            "time": "PT11H11M0S",
            "datetime": "\/Date(489409211999)\/"
        }, {
            "__metadata": {
                "type": "d000000trial.dev.sapui5_date_poc.service.datetime.datetimeType",
                "uri": "https://s8hanaxs.hanatrial.ondemand.com:443/d000000trial/dev/sapui5_date_poc/service/datetime.xsodata/datetime('0000000003')"
            },
            "id": "0000000003",
            "date": null,
            "time": null,
            "datetime": null
        }, {
            "__metadata": {
                "type": "d000000trial.dev.sapui5_date_poc.service.datetime.datetimeType",
                "uri": "https://s8hanaxs.hanatrial.ondemand.com:443/d000000trial/dev/sapui5_date_poc/service/datetime.xsodata/datetime('0000000008')"
            },
            "id": "0000000008",
            "date": "\/Date(1458086400000)\/",
            "time": null,
            "datetime": null
        }, {
            "__metadata": {
                "type": "d000000trial.dev.sapui5_date_poc.service.datetime.datetimeType",
                "uri": "https://s8hanaxs.hanatrial.ondemand.com:443/d000000trial/dev/sapui5_date_poc/service/datetime.xsodata/datetime('0000000009')"
            },
            "id": "0000000009",
            "date": "\/Date(1458086400000)\/",
            "time": "PT17H14M0S",
            "datetime": null
        }, {
            "__metadata": {
                "type": "d000000trial.dev.sapui5_date_poc.service.datetime.datetimeType",
                "uri": "https://s8hanaxs.hanatrial.ondemand.com:443/d000000trial/dev/sapui5_date_poc/service/datetime.xsodata/datetime('0000000010')"
            },
            "id": "0000000010",
            "date": "\/Date(1458086400000)\/",
            "time": "PT17H14M0S",
            "datetime": "\/Date(1458145106553)\/"
        }, {
            "__metadata": {
                "type": "d000000trial.dev.sapui5_date_poc.service.datetime.datetimeType",
                "uri": "https://s8hanaxs.hanatrial.ondemand.com:443/d000000trial/dev/sapui5_date_poc/service/datetime.xsodata/datetime('0000000011')"
            },
            "id": "0000000011",
            "date": "\/Date(489110400000)\/",
            "time": "PT9H43M0S",
            "datetime": "\/Date(489189600000)\/"
        }, {
            "__metadata": {
                "type": "d000000trial.dev.sapui5_date_poc.service.datetime.datetimeType",
                "uri": "https://s8hanaxs.hanatrial.ondemand.com:443/d000000trial/dev/sapui5_date_poc/service/datetime.xsodata/datetime('0000000012')"
            },
            "id": "0000000012",
            "date": "\/Date(552528000000)\/",
            "time": "PT11H11M0S",
            "datetime": "\/Date(518414760000)\/"
        }]
    }
}