We can count backward by days or by weeks. Count a few weeks back to find that February $$6$$ is a Friday. Then count a few days back to find that February $$1$$ is a Sunday. 
If $$13^{}\text{th}$$February is Friday, what day of the week is $$1$$\textsuperscript{st~}February? 

1: Sunday　 
2: Monday　 
3: Wednesday　 
4: Thursday　 
5: Saturday　 