[header] How to make a reasonable excuse to miss a date [title] Explain the feelings that are preventing you from coming. [step] If you are trying to make an excuse, you must have a reason. If it's a reason the person you are supposed to meet will understand, offer it. 
[substeps] If your reason is about you, it might not offend. If you are too tired, too sick, too overworked, or too depressed to meet up, say so.