I need to the date three days from today. On CentOS, I can run the below command.
date -I -d "-3 days"
Which outputs
2022-07-02
I need the same inside my Docker container which is running on Alpine Linux 3.14.6v.
When I execute the same command I am getting the error:
date: invalid date '-3 days'
Anyone knows the workaround for this?
CodePudding user response：
From StackExchange.com:
BusyBox/Alpine version of date doesn't support -d options, even if the help is exatly the same in the Ubuntu version as well as in others more fat distros.
To work with -d options you just need to add coreutils package
CodePudding user response：
A way to do it could be to use a bit of arithmetic on a timestamp, then translate the timestamp back into a date:
date -d "@$(( $(date %s) - 3 * 24 * 60 * 60 ))"
Given
docker run --rm alpine:3.14 sh -c 'date;
date -d "@$(( $(date %s) - 3 * 24 * 60 * 60 ))"'
It would yield:
Tue Jul 5 11:51:31 UTC 2022
Sat Jul 2 11:51:31 UTC 2022