A question which appears in almost everyone who recently joins adsense. Actually i was also concerned and confused about the exact date when adsense will release payment for my monthly (and previous) earning once i reached the threshold.
Adsense starts checking for your previous payments to verify them once you have reached the payment threshold at the end of every month. But this verification takes a while and your payment date is prescribed to be couple of weeks later.
Anyway, so we come back to the point, where exactly shall we find information about when will we get paid from Google Adsense. The information about your payment date is in payment history section of your adsense account.
To goto payment history page, login to your adsense account from www.google.com/adsense. Once logged in you are now on the reports page of your adsense account. There you can see a link to your payment history page (check the following image for the position of the link)
Once clicking on the view payment history link in your Google AdSense reports overview page, it will take you to the payment history page. There (if your payment has been scheduled by Google after verifying it) you can see the exact date for your next scheduled payment (image below for detail) That can be to bank account or to western union, both. However check may take longer than the date mentioned on the payment history page by google due to standard procedure.
You can also reach this page by going to: Google Adsense > My Account > Payment History
You can see message similar to this there:
You are scheduled to be sent a payment by the 30th of this month. If you’re receiving a standard delivery check, please allow up to 4 weeks for delivery, depending on your location. If you’re using EFT or secured express delivery, your payment should arrive by the 5th of next month. Learn more…