Within only a few weeks the flower bud has grown to a considerable size.
Last year I was seriously freaking out at this point because I feared that the flower bud would open while I was away. And I didn't know how long it would take from this point on until it finally opened.
This year I know that it won't take that long. Today there is already a lot of pink visible at the tip (maybe I'll take more photos today). And I guess that the flower bud will open tomorrow night or Monday night at the latest.