Once a while is nice to measure elapse time on Linux on bash command line.
Here is an example how to count elapsed seconds:
$ time1=`date +"%Y-%m%d-%H:%M:%S";time1s=`date +"%s"`
$ time2s=`date +"%s"; echo Elapsed time since $time1 is `expr $time2s - $time1s` seconds
Elapsed time since 2019-1213-19:03:24 is 55 seconds