Using the Line Tool (U), it’s possible to create a kind of calendar table of white color (holding up the Shift button).

Represent now the indicator of the current day applying the Rectangle Tool (U) and the next color – F2F2F2.

Using the Rounded Rectangle Tool (U), try to create the primary layer designed for the site’s menu’s buttons.

The layer’s parameters:
Blending Options>Drop Shadow

Blending Options>Gradient Overlay

Gradient’s parameters: