Getting time and dividing by two in a bash script how to implement?

Question

linux

I am writing one script and I don’t understand how, at the beginning of the actions it gives the initial time, for example, 17:00
after compilation, it will take about 40 minutes and at the end the script will check the time again and give out 17:40
And so that the script divides 1740 by two and gives the result. Thanks in advance

Answer 1

man date unix format
time=$(date +%s)
i = $(( ($finifh - $start)/2 ))
via
let let conec="($fin-$st)/2"