Success Email and Time - Date Function

Success Email and Time - Date Function

My first question is:

is it still possible to send a success email like this:

sendmail
(
To : "imax84@gmx.de"

From : input.e INSTEAD of zoho.loginuserid e stands for an email
address that the
user wrote into the form earlier

Subject : "Neue Abrechnung"
Message : input.nn + " " + input.vn + " hat soeben eine neue Abrechung eingestellt!"
)

My second question is:

How can i work / calculate with the new Date-Time form?
Is it possible or not?
f.e. if i would need it to calculate the money that someone get for a business journey.
and the daily rates are:
30 $ for 24 hours
20 $ for more than 14 hours
10 $ for more than 8 hours