I agree that those DST changes bear the risk to lose the CDP bonus.
borntobesting: the CDP timer does not change so now it resets an hour earlier.
Pardon me, I think not.
The local clocks were advanced by one hour, so (as an example) 4 pm EST became 5 pm EDT, correlating to midnight GMT.
Thus, 'mericans have an hour more to play on the old day.
Those playing on the new day (after 4 pm EDT) will play on the same day twice and gain their CDP a day later. They only must not fail to finish this game until 5 pm.
In case of doubt, the CDP clock in the game menu will show the truth ;)