Nikko All Area Pass purchase

I want to buy Nikko all area pass at the Tobu tourist information center Asakusa at 28th of September but my first use of the pass will be at 18th of October. Can I do it or a purchase of the pass must be just before a first use?

- Tobu Railway: NIKKO PASS all area
http://www.tobu.co.jp/foreign/en/pass/all.html

It seems:
this pass, initially at the issuance,
has a blank space for the period of its validity,
and later the actual dates are stamped there.

On the web, you find submitted photos
of this pass with dates stamped,
and of its sample with that space blank.

at the Tobu tourist information center Asakusa

From which place would you head there?

Note:
To take a Tobu Limited Express train,
you purchase a separately ticket;
for your ride in the validity area of this pass,
you get a 20 percent discount on the surcharge;
so make sure to present your pass.

Enjoy your trip!