Recent customers of the West Village’s Alta should check their old calenders to make sure that they didn’t eat at the tapas restaurant between March 23 and April 2, because those who did are at risk of contracting Hepatitis A and should get vaccinated immediately, according to the city Health Department. The good news is that the possible contamination is limited to the dessert menu, because the restaurant’s pastry chef, who contracted the disease on a trip to Mexico, is the only infected employee. She is no longer “on the premises,” and the restaurant is telling patrons that dessert is unavailable due to a broken oven. “We’re not trying to scare anybody,” one waiter told the New York Post when asked about the lack of posted warnings. Meanwhile, Alta said that only about 15 percent of the 3,000 people who ate there during 11-day span ordered dessert, which means that there are at least 450 people who should definitely get themselves to the Chelsea Health Center, where free vaccinations are being offered through Monday. Everyone else: Congrats on sticking to those diets.