Type mismatch error when updating a Date

Questions
1

Following your instruction @cocreature offline, i used the function
getToday : Update Date
getToday = toDateUTC <$> getTime

but when i use it inside a choice, thats creating a contract, I am getting a type mismatch error
create Token with
issued = getToday – The error is on this line, expected type “Date”, but actual type is " Update Date".

How can i solve this and what is the purpose of Update

2

Think of Update a of a description that when executed will perform some (potentially side-effecting) operations and produce a value of type a.
You need to bind the result using <-., so issued <- getToday. I recommend to read the [corresponding section in the Daml docs for a much more comprehensive intro to Update and other instances of the Action class.