The first search result concurred with Brandon. However, it also mentioned a nice little bit of information that sounds like something I would write. On a page whose sole purpose is to inform people about DST, there is a lecture on spelling and grammar.
The official spelling is Daylight Saving Time, not Daylight SavingS Time.
Saving is used here as a verbal adjective (a participle). It modifies time and tells us more about its nature; namely, that it is characterized by the activity of saving daylight. It is a saving daylight kind of time. Similar examples would be a mind expanding book or a man eating tiger. Saving is used in the same way as saving a ball game, rather than as a savings account.Nevertheless, many people feel the word savings (with an 's') flows more mellifluously off the tongue. Daylight Savings Time is also in common usage, and can be found in dictionaries.
Adding to the confusion is that the phrase Daylight Saving Time is inaccurate, since no daylight is actually saved. Daylight Shifting Time would be better, but it is not as politically desirable.