ls -lah --color --time-style=+%F

# will output year-month-day like: 2020-02-06
# if one needs the actual TIMESTAMP: go --full-time
# ls -lah --color --full-time will output time in format:
# 2020-02-04 11:37:57.619196543 +0100

# can put it into (debian/ubuntu/mint...)
vim /etc/bash.bashrc
# can put it into (fedora/redhat/centos...)
vim /etc/bashrc

# as shortcut: ll
alias ll="ls -lah --color --time-style=+%F"

example output:

admin