【shell】bash: +%Y-%m-%d: command not found...

Enclose the entire value in backquotes.

[root@znrmdapp1 ~]# date=date '+%Y-%m-%d'
bash: +%Y-%m-%d: command not found...
[root@znrmdapp1 ~]# date=`date '+%Y-%m-%d'`
[root@znrmdapp1 ~]# echo $date
2020-12-18
[root@znrmdapp1 ~]#