bash ${SCRIPT}

#!/bin/bash
#
date1=$(date -d now --iso-8601)
date2=$(date --date="$(openssl x509 -in /etc/pki/tls/certs/postfix.pem -enddate -noout | cut -d= -f 2)" --iso-8601)
start_ts=$(date -d $date1 '+%s')
end_ts=$(date -d $date2 '+%s')
echo "Statistic.DaysToCertExp: $(( ( end_ts - start_ts )/(60*60*24) ))"
exit 0