How to set Time picker dynamically

Dear all,
i need help to understand if it’ s possible mange the time picker values from code.

i try to explain my requirement:

On the top of the dashboard i have a dropdown menu to chose which turn i want to analyse
for example a daily shift of work with id 1406 starter at 01/04/2019 05:30 and ended 01/04/2019 22:100:
I do a time table from set of data, my key is an identify of a daily session (a number)
my problem is the timepicker on the top right of the dashboard, because the view of my data on the graph is bonded by the timepicker.

it’s possible set the timpicker value from and to by global variable dynamically?
it’s possible free the graph time range showed from the timepicker?

Thanks in advance for any helping

… no reply?