In your Result section, create a new computed column with "Sysdate()", and it will generate the current system date. Then you can add this date to your Report or Dashboard showing when this query is run.
var TestDate = ActiveDocument.Sections["Results"].GetCell(1,1)
ActiveDocument.Sections["Dashboard"].Shapes["TextLabel5"].Text = "Today is: " + TestDate;
In your "Results", create a new computed column with "Sysdate()" and move it to column 1.
Add an Element to your dashboard by dragging a "Text Label"; modify the Script and Property of the Text Label.
if you have today's date as an column in a Query then you will need to do GetCell() from that results section and assign to the Text property of a Text Label or Text Box.
The assigning of that text to the object can be done under a Command Button or OnActivate of the Dashboard or OnStartup of the BQY
var dToday = new Date()
var sYear = dToday.getFullYear()
var sMonth = dToday.getMonth()+1 // 0 based index
var sDay = dToday.getDate()
var sToday = sMonth + '/' + sDay + '/' + sYear