To investigate this further, I took a look at the team's record from the month of April for the past several seasons:
2009 - 12-10
2008 - 14-15
2007 - 9-14
2006 - 13-10
2005 - 10-14
2004 - 11-10
2007 and 2005 were poor starts to be certain, but more than anything else these results tell me that the team's reputation for starting slow is undeserved. For example, the 2009 team's 12-10 start translates to a record of 88-74 over the course of 162 games. The team's April start didn't leave them on pace to win their eventual total of 103 games, but that's not a bad pace to open the season, particularly when one considers all the roster changes that occurred between April and June.
Furthermore, with the exception of October, the 2009 Yankees played above .500 baseball every month of the season. They went 17-11 in May. Looks, therefore, can be deceiving. I would have guessed that the team would have been .500 or worse in April for most of the recent seasons. I would have been wrong.
It may not seem like it, but if the Yankees go 12-10 in April then they're on the same pace they set in 2009. 24 days to the start of the season!