Linux Date Snippets

source: https://unix.stackexchange.com/questions/24626/quickly-calculate-date-differences

* date --utc -d 'mar 28 1867 +72years +11months +2days'
* expr $(date '+%s' -d 'Aug 02, 2020') - $(date '+%s' -d 'Aug 01, 2020')

get recipient from maillog

source: https://superuser.com/questions/178171/gnu-sort-by-case-sensitive

awk -F"[<>]" '{print $2}' maillog | grep -i $recipient |  LC_COLLATE=C sort --ignore-case | uniq -i