Originally Posted by show_me_the_points

Learned something important today. The time-frame to complete your spend starts from the first of the month in which you have applied/approved for the card. I always assumed it was from when you applied. But here's a response from Citi for a card I applied on 4/13/13

The promotional offer on your account allowed you to earn 45,000 bonus miles after making $5,000.00 in purchases within four months of the account opening. We show you did not meet the purchase requirement within four months, and the offer expired. The offer was valid between 04/02/2013-08/02/2013. We show you made total purchases of $4546.39.