"If you say you will come at four o'clock in the afternoon, I will feel very happy from three o'clock. The closer the time is, the happier I will be. By four o'clock, I will be on pins and needles. I have found the value of happiness, but if you come at any time, I don't know when I can satisfy your mood. "
The Little Prince by Saint Exupery
I wonder if this is what you want.