Greetings from Syncfusion support.
You can disable the time zone conversions by setting timeZone property to false in sample. Refer to the following code
<ej:DateTimePicker ID="DateTimePicker1" runat="server" Value="13/1/2020 4:00 PM" TimeZone="false" ></ej:DateTimePicker>
This will display the same date and time in the control irrespective of the user's time zone. Please refer to the following forum for more details on this.
Kindly get back to us if you require any further assistance on this.