To diplay todays date:

Markup Text
Displayed as
Today is !today. Today is 11 Dec, 2017.
XML is !today -xml. XML is 2017-12-11T18:53:11.
Right now it is !today -t. Right now it is 11 Dec, 2017 18:53.
Tomorrow is !today +1. Tomorrow is 12 Dec, 2017.
Last week was !today -7. Last week was 04 Dec, 2017.
The month is !today (MMM). The month is Dec.

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.)