Can I automate database so I set up one date and zoho calculate other dates?

Can I automate database so I set up one date and zoho calculate other dates?

Hey, 

I wanted to ask you and perhaps receive a few pointers on automating adding information to a database. Let's say I have a database that I input a main date. There are many date fields that I would like zoho to automatically fill based on this date. For example, the main date I fill is start of event. I would like to know how to make zoho automatically input date in other field, for example purchase a flight, which I want to always appear 2 weeks before the main date. Any ideas how I could do that? 

Thanks!