When "setDate, null" time not reseting in widget

[YakutD]

I m trying to make reset fo form, which has field dattimepicker. I was trying:

modal.find('.datepicker').datetimepicker( "setDate", null );

but only date was unset, not time. How to fix it?

[YakutD]

My altfield was reseted, main field too, but not in widget ._.