Date calculations

Question

I'm building a LaTeX document that helps me to formulate quotations for my customers. Since I decided to offer monthly recurring payments I'd like to have payment dates calculated automatically starting from a specific one. Say, for example, that you have:

\today{}

then I need to have:

• \today +30 days
• \today +60 days
• \today +180 days

and so on...

Is that possible?

EDIT: I ended up using the package advdate because I obtained a more compact result to do this:

% Payment starts in 4 months.
\AdvMonth{4}

% 1 chunk per month -> due date:
\begin{enumerate*}
    \AdvMonth{1} \item due date: \textbf{\today}
        ...
\end{enumerate*}

Answer 1

See the advdate package.

Answer 2

This is possible with the datenumber package

\documentclass{article}
\usepackage{datenumber}

\begin{document}

\setdatetoday
\addtocounter{datenumber}{30}%
\setdatebynumber{\thedatenumber}%
In 30 days is \datedate

\setdatetoday
\addtocounter{datenumber}{60}%
\setdatebynumber{\thedatenumber}%
In 60 days is \datedate

\setdatetoday
\addtocounter{datenumber}{90}%
\setdatebynumber{\thedatenumber}%
In 90 days is \datedate

\end{document}

Which results in: