Demonstrate date handling in shell.
To get GNU gdate on a Mac you'll need to install coreutils
brew install coreutils# Tue May 10 08:56:10 BST 2022
gdate
# convert timestamp back to datetime "Fri Sep 17 16:13:36 BST 2021"
gdate --date=@1631891616
# date two days ago "Sun May 8 08:56:57 BST 2022"
gdate --date="2 days ago"
# date two days ago as timestamp "1651996634"
gdate --date="2 days ago" '+%s'
# Include nanoseconds "2022-05-10 08:57:25.611297000+01:00"
gdate --rfc-3339=ns
# Include nanoseconds "1652169462.931413000"
gdate +%s.%N
# Filesafe datetime
gdate "+%Y%m%d-%H%M%S"# date yesterday as timestamp "1652083103"
date -v-1d '+%s'- How To Format Date And Time In Linux, MacOS, And Bash? here