A new group of characters has just turned up on Urban Rivals - the legendary characters. They are not available in the shop and cannot be exchanged between players. There's only one way of getting hold of them and that’s by winning them! Each legendary character is linked to one or several missions that allow you to win them. But be warned, these missions have a time limit and you must complete the mission before the deadline is up to win the character. When there are no missions left allowing you to win a legendary character, you can still play for it. However, to make it available again, you must wait for a new mission to appear in which you can win it. The time this takes may vary. So, you haven’t got a moment to lose! Click here now to meet the legendary characters : http://www.urban-rivals.com/missions/legendary/
I don't remember for certain when Lois was scheduled to expire, but remember that the game is based on Paris time, GMT+1. So, it's entirely possible it may still have appeared to be a 'valid' date to you, but the game had already moved past midnight, and onto the next day.