I tried to change the clock on the control timer. Now it has gone blank and is flashing. help

[sghi]

Everything has gone blank.  The days of the week are now small flashing triangles and no "on/off" time periods are visible.

I can't get the flashing to stop.

How do I reset the timer control?

Also, the button marked "CL" is stuck in.

Sorry - can't do this in German!!

[Franky]

First set the day of the week. So should the time appear again.