How do I have a long date on home screen?

Question

I am new to Ubuntu and I am not sure if I can have a long date that has one of the following format:

dd/mm/yyyy hh:mm am/pm or dd-mm-yyyy hh:mm am/pm or dd mm yyyy hh:mm am/pm

or

dd/month/yyyy hh:mm am/pm or dd-month-yyyy hh:mm am/pm or dd month yyyy hh:mm am/pm