IDC: Mac shipments down. Gartner: Mac shipments up.

It must be tough to be a market research firm these days. IDC released preliminary information of PC shipments for the first calendar quarter of 2013 today, showing the market to be dismal with an overall decline in PC shipments of almost 13 percent in the US year-over-year and Mac shipments apparently down 7.5 percent in the same period. On the other hand, Gartner's figures -- also released today -- show an 9.6 percent year-over-year decline in the US PC market, and shipments of Macs actually growing 7.4 percent in the same period.

With Apple's fiscal second quarter earnings report coming up in less than two weeks, the conflicting numbers are sure to make financial analysts reach for the bottle of Jim Beam hidden in a desk drawer. As if the numbers from IDC and Gartner weren't perplexing enough, 9to5Mac points out that NPD Group's numbers show sales (not shipments) of Macs jumping a whopping 14 percent.

Who's right? We'll all have to wait until the afternoon of April 23 to see the actual numbers from Apple. If history repeats itself once again, we're sure to see stellar numbers from Apple for most product lines, followed by a precipitous drop in AAPL's share price. You can join us for all the fun during our regular earnings call liveblog at 5 PM ET on April 23, 2013.