This provides an XPages way of failing over on mobile devices to use the native / mobile browser's date/time controls with correct formatting to save back into a Notes Document as the correct Notes Item type.

mobile date control snippets.xml

<!--

mobileLib.isMobile() returns boolean of whether the current device's user agent string
matches a mobile browser (iPhone, iPad, iPod, Android, etc.)
modified version of src: http://openntf.org/XSnippets.nsf/snippet.xsp?id=read-user-agent

dateTimeLib.dateFormatMobile = (!mobileLib.isMobile()?"MM/dd/yy":"yyyy-MM-dd");

dateTimeLib.timeFormatMobile = (!mobileLib.isMobile()?"hh:mm a z":"hh:mm");
-->

<xp:inputText
	id="someDateField"
	value="#{document1.MyDate}"
	defaultValue="${javascript:!mobileLib.isMobile()?@Today():null}"
	type="date"
	disableClientSideValidation="true">
	<xp:this.converter>
		<xp:convertDateTime
			pattern="${javascript:return !mobileLib.isMobile()?dateTimeLib.dateFormatUI:dateTimeLib.dateFormatMobile;}"
			type="date">
		</xp:convertDateTime>
	</xp:this.converter>
	<xp:dateTimeHelper
		id="dateTimeHelper1"
		loaded="${javascript:return !mobileLib.isMobile()?true:false;}">
	</xp:dateTimeHelper>
</xp:inputText>

<xp:inputText
	id="someTimeField"
	value="#{document1.MyTime}"
	type="time"
	disableClientSideValidation="true"
	style="min-width:6em;min-height:1em;"
	defaultValue="${javascript:!mobileLib.isMobile()?@Now():null}">
	<xp:this.converter>
		<xp:convertDateTime
			pattern="${javascript:return !mobileLib.isMobile()?dateTimeLib.timeFormatUI:dateTimeLib.timeFormatMobile;"
			type="time">
		</xp:convertDateTime>
	</xp:this.converter>
	<xp:dateTimeHelper
		id="dateTimeHelper2"
		loaded="${javascript:return !mobileLib.isMobile()?true:false;}">
	</xp:dateTimeHelper>
</xp:inputText>