Use timepicker selection in query

Anyone know if it is possible to use the time picker selection in a query?

I would like to use this value to calculate availability of a server in base of the time range selected.

time picker 24 so time_interval = 24 hours

server time_offline time_interval availability server1 3 hours 24 hours 87,5% server2 20 hours 24 hours 26,7%

I mean, I have the number of time downtime but I can’t calculate this metric dynamically.

Thanks!