date是Linux系统里自带的一个系统命令，用来显示当前的系统时间，不过默认显示的结果里包括很多信息，特别是做为文件名输出时，不是很方便 好在date命令里包含格式化输出的选项。
$ date "+%Y-%m-%d"
2020-08-09
$ date "+%Y-%m-%d %H:%M:%S"
2020-08-09 17:51:17
FEATURED TAGS
algorithm
algorithmproblem
architecturalpattern
architecture
aws
c#
cachesystem
codis
concurrentcontrol
database
dataformat
datastructure
debug
design
designpattern
distributedsystem
django
docker
domain
engineering
freebsd
git
golang
grafana
hackintosh
hadoop
hardware
hexo
http
hugo
ios
iot
java
javaee
javascript
kafka
kubernetes
linux
linuxcommand
linuxio
lock
macos
markdown
microservices
mysql
nas
network
networkprogramming
nginx
node.js
npm
oop
openwrt
operatingsystem
padavan
performance
programming
prometheus
protobuf
python
redis
router
security
shell
software-testing
spring
sql
systemdesign
truenas
ubuntu
vmware
vpn
windows
wmware
wordpress
zookeeper