If you’re living in Hell, you may want to put a sweater on, as it’s likely to be getting colder by the second: Apple has now passed Microsoft in both revenue and earnings for the first time since Ronald Reagan was president. On Thursday, Microsoft announced revenue of US$16.43 billion and earnings of $5.23 billion for the March quarter, well behind Apple’s revenue of $24.67 billion and earnings of $5.99 billion.

Apple passed Microsoft on the revenue side in the September quarter of 2010, as you can see in the chart below. It took three more quarters for Apple to pass its erstwhile foe in profits, however, in part because of the disparate nature of the two companies’ business models.

Apple and Microsoft revenues in billions by calendar quarter since Q1 of 2009

Data compiled by The Mac Observer

The vast majority of Microsoft’s business is software, a business with very high gross margins, and therefore higher profit margins. Apple, on the other hand, is a hardware company, and while the Mac, iPhone, and iPad maker has far higher margins than any other PC maker on the planet, the company’s margins still don’t touch Microsoft’s.

In the March quarter, however, Apple was able to bring enough revenue to the table to overcome the gross margin difference and turn in higher profits than Big Redmond, which you can see in the chart below.

Apple and Microsoft earnings in billions by calendar quarter since Q1 of 2009

Data compiled by The Mac Observer

A combined chart showing revenue and earnings (in billions) for Apple and Microsoft

Data compiled by The Mac Observer

For those keeping score at home, Apple passed Microsoft in terms of market cap (the value of a company as determined by the stock market) back in May of 2010. Today, Apple has a market cap of $320.7 billion, as compared to Microsoft’s $224.4 billion.

Oh well, at least Microsoft still sells more copies of Windows than Apple sales Macs. That’s something, right?

Shares in Microsoft ended the day higher at $26.71, up $0.330 (+1.25%), on heavy volume of more than 80 million shares trading hands.

AAPL ended the day lower at $346.75, down $3.40 (-0.97%), on light volume of 12.9 million shares.

*In the interest of full disclosure, the author holds a small share in AAPL stock that was not an influence in the creation of this article.