After a stamped Visa from Canada, within How many month can we fly to Canada.

[mdhkr]

I have forwarded my papers to the AbuDhabi Embassy for processing Visa for Temporary foreign worker, As it says it can take for 6weeks.
If i get a visa with in how many days or month do i need to fly to canada. is there any visa expiration if i didnt travel for certain period.
I am looking forward to have a answer for this from the Experienced.... thanking you..

[Editsniper]

as soon as you get your visa you can use it the very next day if u decided to, and yes the visa does have an expiration date and the date would be posted on the visa and you would have until that expiration date to use it to come to Canada and i did read it somewhere that usually the expiration date is 6 months or 1 year to use it from the date it was stamped, then once you get into Canada then u apply for PR card and thats usually good for 5 years but after the 3rd year you can apply to be Canada citizen