(Crain’s) — McDonald’s Corp. posted strong March sales at U.S. restaurants, according to estimates from two analysts. Analyst Mark Kalinowski’s survey of 213 U.S. McDonald’s found average sales increased 5.1% in March from the year-earlier period. McDonald’s U.S. sales increased 2.8% in February compared with February 2008, but the restaurant chain said the rise would have been 6.8% in February if it weren’t for the month having one less day than in 2008. Global sales increased 1.4% in February, or about 5.4% without the calendar shift.