I have an aura component which is constructed like this

```
<aura:attribute name="newEvent" type="Event" default="{ 'sobjectType': 'Event'}"/>

<lightning:input
    aura:id="startdatetime"
    type="datetime"
    label="Start Time"
    name="start"
    value="{!v.newEvent.startTime}"
    required="true"
/>

<lightning:input
    aura:id="enddatetime"
    type="datetime"
    label="End Time"
    name="end"
    value="{!v.newEvent.endTime}"
    required="true"
/>

```

How do I add 1 hour to end date time based from start date time? For example start date time is 20/07/2022 3:10 pm, I want the end date time to be 20/07/2022 4:10 pm and set it to input field as default value.