index=* | head 1 | eval TodaysDate=strftime(now(), "%Y-%m-%d") | table TodaysDate
Would give you:
Are you looking to do something more specific?
Could you provide more details on the requirement here? You want to add a date field in the result of the search/report OR you want to current date to be shown on a dashboard OR you want the date to be put on email alert of a report?