Install watch

$ sudo brew install watch

iTerm or Terminal（终端）

simple code

$ watch -t -n1 "date"

2016    3 29        20  33 54   CST

watch && figlet

$ watch -t -n1 "date +%T|figlet -f banner"

 #####    ###    #   #####  #        #  #        #####
#     #  #   #  ### #     # #    #  ### #    #  #     #
      # #     #  #        # #    #   #  #    #  #     #
 #####  #     #      #####  #    #      #    #   ######
#       #     #  #        # #######  #  #######       #
#        #   #  ### #     #      #  ###      #  #     #
#######   ###    #   #####       #   #       #   #####

• Homebrew