What day in the week has Sun in it

What day in the week has day in it?

$$\frac{\partial x}{\partial y}\frac{\partial x}{\partial y}\frac{\partial x}{\partial y}\frac{\partial x}{\partial y}\frac{\partial x}{\partial y}\prod_x^y\prod_x^y\overrightarrow{xy}\overrightarrow{xy}\overrightarrow{xy}\pm\pm\infty\infty\propto\rightarrow\beta+P\Pi\Psi\forall\theta\times0=?$$