The date picker currently has the following issues on both Safari and Firefox:

• the arrows in the header are not vertically centered (they are a bit too high up)
• there's a one line gap in cells with a background color
• the should be a gray line separating the last row of the calendar from the row containing the time picker
• please horizontally center the time picker and maybe add 1 or 2 px top/bottom paddings in the row that it contains

On Firefox only:

• the currently selected cell has a drop shadow (see second screen shot) - please remove it