The issue was that in some conditions wrong format of the date was pass to the sever, and it was not parsed correctly. This was solved several weeks ago and it should work correctly in the latest internal builds
. We are also working on some improvements for transferring and parsing the selected date for RadDateInputs and RadDatePickers.
Currently If you have problems with submitting the date when the inputs is in focus and another script or controls is making the callback, it would be best to set EnableSingleInputRendering property of your inputs to "false" and it should work correct in all cases. Meanwhile we are working on some fixes that will allow to submit the proper value of the control regardless of its focus state.
the Telerik team
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