[SalesForce] Get only time from Datetime field

Use Apex to get User's TimeZone and offset time. e.g.

<apex:page controller="TimeZoneController">
    <apex:outputText value="{0,date,dd/MM/yyyy HH:mm:ss}">
        <apex:param value="{!NOW()+offset}"/>
    </apex:outputText>
</apex:page>

public class TimeZoneController{
    public Double offset{get{
        TimeZone tz = UserInfo.getTimeZone();
        //Milliseconds to Day
        return tz.getOffset(DateTime.now()) / (1000 * 3600 * 24.0);
    }}
    public TimeZoneController(){
    }
}

[Reference] https://www.xgeek.net/salesforce/display-datetime-with-timezone-in-visualforce-page/

You can remove the input field from the page by using CSS that is qualified by the element name (i.e. hide the input.hideField but not the a.hideField as the styleClass is applied to both the field and the lookup icon):

<apex:page standardController="Contact">

<style>
input.hideField {
    display: none;
}
</style>

    <apex:form>
        <apex:inputField value="{!Contact.AccountId}" styleClass="hideField"/>
    </apex:form>

</apex:page>

The input field remains in the DOM and is populated by the selection from the popup.