The day before you plan to serve the chicken, drain the yogurt. Place the yogurt in a strainer lined with cheese cloth placed in a bowl, and refrigerate for 6 hours. Remove the yogurt from the strainer. In a medium-sized bowl, whisk the ginger and the lime zest into the yogurt, cover, and refrigerate for at least 8 hours, or overnight. Remove the yogurt from the refrigerator and strain it through a fine-mesh strainer, to remove the ginger and the lime. Reserve at room temperature.