1) choose your day and starting time

2) click and drag the sniplet and release the mousebutton at your desired ending time

3) choose your activity in the arising context menue

4) how to modify your sniplet:

   to change your activity just click on the single column

   to modify your sniplet's length, just catch the cursor at the outer right border and adjust by dragging your mouse

   drag the sniplet as a whole to change the starting point