Given that April $$15$$, $$2011$$ was Friday, what day was May $$11$$, $$2011$$? 
Overseas Competition->Knowledge Point->Word Problem Modules->Periodic Problems->Periodic Problems of Time
Counting from April $$15$$, $$2011$$, after $30-15=15$ days it will be April $$30$$, $$2011$$. After $11$ days, it will be May $$11$$, $$2011$$. In total, there are $15+11=26$ days. $26\div 7 =3R5$, which means May $$11$$, $$2011$$ was Wednesday. 