Samples

On Linux, just use as date. On macOS, you’ll need to setup gdate and then use that instead below with the same arguments.

Today

  • Default. 
      $ gdate
  Wed Aug 26 19:44:35 SAST 2020
  • Date. 
      $ date +%Y%m%d
  20200826
  $ date +%Y-%m-%d
  2020-08-27
  • Unix Timestamp. 
      $ date -d "Oct 21 1973" +%s
  120002400

A target Unix Timestamp date.

$ date --date @120024000
Sun Oct 21 06:00:00 SAST 1973

Difference

$ date --date="next day" +%Y-%m-%d
2020-08-27

$ date --date='5 minutes ago'; $date; date --date='5 minutes'
Wed Aug 26 19:44:48 SAST 2020
Wed Aug 26 19:49:48 SAST 2020
Wed Aug 26 19:54:48 SAST 2020

Advanced

Copied from date --help. Show the local time for 9AM next Friday on the West coast of the US.

$ date --date='TZ="America/Los_Angeles" 09:00 next Fri'
Fri Aug 28 18:00:00 SAST 2020

Setup on macOS

On macOS, the GNU Linux one can be installed:

brew rm coreutils && brew install coreutils

$ which gdate
/usr/local/bin/gdate

$ gdate
Wed Aug 26 19:27:24 SAST 2020

Use GNU Linux date on macOS

You can then add an alias to the macOS system uses gdate instead.

alias date=gdate

CLI

$ date --version # Linux
$ gdate --version # macOS

date (GNU coreutils) 8.32
Copyright (C) 2020 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later <https://gnu.org/licenses/gpl.html>.
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.

$ man date

DATE(1)                                    User Commands                                    DATE(1)



NAME
       date - print or set the system date and time

SYNOPSIS
       date [OPTION]... [+FORMAT]
       date [-u|--utc|--universal] [MMDDhhmm[[CC]YY][.ss]]

DESCRIPTION
       Display the current time in the given FORMAT, or set the system date.

       Mandatory arguments to long options are mandatory for short options too.

       -d, --date=STRING
              display time described by STRING, not 'now'
       ...