To diplay todays date:

Markup Text
Displayed as
Today is !today. Today is 27 May, 2017.
XML is !today -xml. XML is 2017-05-27T15:49:26.
Right now it is !today -t. Right now it is 27 May, 2017 15:49.
Tomorrow is !today +1. Tomorrow is 28 May, 2017.
Last week was !today -7. Last week was 20 May, 2017.
The month is !today (MMM). The month is May.

As you can see, you can add or subtract days. You can include the time tiwh -t. And you can use your own format for the time. (See SimpleDataFormat for the syntax.)