The amazing date command

I use the Linux date command regularly. Normally I use it to format current date, e.g.

date +"%Y-%m-%d"

Yesterday, while writing a backup script, I found out that the command also understands simple English. E.g.

date +"%Y-%m-%d %H:%M:%S" --date "yesterday"
date +"%Y-%m-%d %H:%M:%S" --date "-7days"
date +"%Y-%m-%d %H:%M:%S" --date "-7days 00:00:00"
date +"%Y-%m-%d %H:%M:%S" --date "2 weeks ago"

This helps when I want a date that represents, say, 3pm yesterday.