Respuesta: Problema con datepicker e idioma        yo personalmente, tuve el mismo problema.   
mira, si te metes al codigo del jQuery, pero no al min, que no vas a poder leer,  
y buscas el datepicker, te encuentras con las variables y todo,  
Yo cambia ( fuerza bruta) todo ese codigo,  
quedo en español 100%, pero si lo quiero cambiar de idioma, cague no mas.   
los lenguajes estan en el sitio de jQuery, asi ke es un copiar pegar y listo.   
asi  
this.regional=[];this.regional[""]={closeText:"Done",prevText:"Prev",nextText:"Next"  ,currentText:"Today",monthNames:["January","February","March","April","May","June",  "July","August","September","October","November","  December"],monthNamesShort:["Jan","Feb","Mar","Apr","May","Jun","Jul","Aug","S  ep","Oct","Nov","Dec"],dayNames:["Sunday","Monday","Tuesday","Wednesday","Thursday"  ,"Friday","Saturday"],dayNamesShort:["Sun","Mon","Tue","Wed","Thu","Fri","Sat"],dayNamesMin:["Su", 
"Mo","Tu","We","Th","Fr","Sa"],weekHeader:"Wk",dateFor   
cambialo y listo (un poco de trabajo no viene mal)   
slds           |