>>>Do you use inputmask, e.g. "99:99" and format "R"?
>>
>>We have InputMask as below and no Format.
>>

>>!!:!! !!
>>

>
>First of all, use "R" format. It will improve this thing, i.e. you will not get :: anymore. You could also make further improvements, e.g. by moving AM/PM part to separate box, or by resetting it in InteractiveChange event.

What is your thought about using the InteractiveChange event to handle the AM/PM?