DateTimeUtc

DateTimeBox UTC

If this Checkbox is activated. You will see the Date time in you local timezone but the value behind the control is a utc (GMT) time. setFieldValue will assume you set a utc time and will add the local timezone just for the display. getFieldValue will give you the utc time as well. So users in different timezones will see different values, but in the database there is just the utc time stored.