When you are all prepared physically and emotionally for a date and they cancel last minute you should post a quick discount offer for that missed time since as the saying goes - once the clock ticks or the plane leaves the gate there is no getting back the time or flight income from that unsold seat.    Offer a quick 50% off since you are all prepared and you can at least earn a slice of bread for that time-frame vs the entire loaf or cake.

Had I only known sooner, darling...