Federal Income Taxation Question

Now that we have decided to become an S Corp after reviewing the various pros and cons, and we have timely filed our S Election on the Form 2553, how do we account for the income? One of the differences between an S Corp and a partnership for example is that allocations of income are made to shareholders on a per-share per-day basis.

Here is an example for us to work through:

The Bridges Corporation, and S Corporation, is owned equally by three shareholders, Carl, David, and Dale. The corporation is on a calendar year basis. (By the way S Corps must use a calendar year end, unlike C Corps which can choose a fiscal year end.) On February 1, 2013, Dale sold his 1/3 interest to Matt. For the year ended December 31, 2013 the corporation had non-separately stated ordinary income of $120,000.

For 2013, how should the income be allocated to the shareholders?