Cyber Dimensions....

you can use Win+B, then Left, then Enter to pop up this calendar with the keyboard (or you can just click once on the clock).

But this can be done with a single keystroke with an AutoHotkey script.

What we'll do is assign the F12 key to send the keystrokes instead of having to do them manually. Create a new file named something.ahk and then paste in the following:

#InstallKeybdHook
#Persistent
#HotkeyInterval,100
SetKeyDelay, -1

f12::
{
send, {lwin down}b{lwin up}
sleep 10
send, {left}
sleep 10
send, {enter}
Return
}

Save the file, and now you can double-click on it to launch it.

At this point you can use the F12 key to pop open the calendar. If you want to close the script out, there's an icon in the system tray.

Note: You can substitute another key instead of F12 if you want. You could also add #NoTrayIcon to keep it from putting an icon into the system tray.

Source:how2geek.com