/usr/bin/cronnext: invalid option -- '-'
unrecognized option: /usr/bin/cronnext
Find the time of the next scheduled cron job.
Usage:
 cronnext [options] [file ...]

Options:
 -i users  include only the crontab of these users
 -e users  exclude the crontab of these users
 -s        do not include the system crontab
 -a        examine installed crontabs even if files are given
 -t time   start from this time (seconds since epoch)
 -q time   end check at this time (seconds since epoch)
 -j cmd    only check jobs that contain cmd as a substring
 -l        print next jobs to be executed
 -c        print next execution of each job
 -f        print all jobs executed in the given interval
 -h        this help
 -V        print version and exit