Deferring the Project Costs & Revenues till certain event

Summary

Require to defer the costs and Revenues till a certain event occurs and then recognize the cost and revenues

Content

for our client, we create a project for a 4 to 5 day event. However preparatory activities for this event starts atleast an year before. Hence various costs and revenues will start flowing into projects from various sources. 

The requirement is, that we realize the cost and revenue only once the actual event finishes or occurs. 

Costs and revenues as of now have no relation but open to any solutions that demands some sort of dependencies. 

Version

20B