Returning a value in a sheet based on current date and time

I have a sheet that tracks deployment of vehicles during each day on an hourly basis. (please see example file below)

I really want to automate the status in cell D1 based on the current date and time (held in G1) from the data below so that the status is always current without having to be updated each time.

Could someone please suggest a formula to solve this problem as I am really not sure how to do that....

Many thanks in advance