On Change Event for Date/Time Field does not set focus to another field properly

We have a date/time attribute with an on_change event that is fired when a date is entered.

Most of the code in the on_change event works as expected except trying to set the focus to another field on the form.

Code used to set focus is:

Xrm.Page.getControl("fieldNameofOtherfield").setFocus(true);

What is odd is that the set focus does work if the user enters the date manually. However if the calendar control is used to select a date then the focus remains on the field and does not move to the desired field.

Robert